When addressing such a question, a few preliminaries are in order. First, How do we define Modern and Sociologists? Starting when, and by what criteria? Yet, skipping the problematics of such delimitations, the case of sociology as an academic discipline is rather simple and straightforward. Sociology (and the social sciences) was born in and of modernity, along with all its complex issues. As the French philosopher Étienne Balibar has claimed, "the couple crisis–critique has determined the programme of the social sciences from the start of the nineteenth century up until today". Thus, we need to figure out who are the best analysts of our communal and social condition. That answers the general question of 'why' we should read sociologists at all. Now, we shall break down this generality - of understanding our common condition - into specific thinkers, sociologists, who contributed most to that shared goal. Each thinker, their differences notwithstanding, contributed something to that understanding, and many of them have coined terms that are (still) being used commonly and publicly.
1. Harriet Martineau
Usually overlooked, one of the most original writers and thinkers who contributed to the establishment of sociology was Harriet Martineau. Born in 1802, she wrote extensively on politics, society, economics, ethics, and religion. Her major contribution is a principle according to which society should be studied comprehensively as a whole, detailing all its facets and aspects. She was also among the first to highlight the importance of studying women and women's issues. Between 1832 and 1834, she published two important works, Illustrations of Taxation and Illustrations of Political Economy. Later, in 1853, she translated and introduced a major sociological work, The Positive Philosophy of Auguste Comte, for the English-speaking reader.
Pictured: Harriet Martineau
2. Emile Durkheim
Officially at least, it would be inconceivable to think of Sociology without thinking of Emile Durkheim, one of its forefathers or founders. His early work, such as The Rules of Sociological Method (1895), captures the basic underpinnings of studying any society whatsoever, and the specificities of modern society. Also, he was able to build a unified methodology for sociological research, based on notions of solidarity and regularity. Later, in The Elementary Forms of Religious Life(1912), he studied the conditions of any possible society, which he found to be rooted in shared beliefs.
3. Gabriel Tarde
At the same time and place, France at the beginning of the 20th century, Durkheim's biggest opponent was Gabriel Tarde. His contribution, albeit recently (re-)discovered, was an alternative route to thinking about society and studying it scientifically. His highly original works, such as The laws of Imitation (1890), Monadology and Sociology (1893), and Social Laws - an Outline of Sociology (1898), provide a fundamentally different approach to what society and "the social" are. His pan-social approach seeks to explicate the inherently social nature of any phenomena. From it, we can draw other conclusions, sites and modes of investigation, compared to the more mainstream (positivist and functionalist) approaches to society and the social.
4. Karl Marx
Moving on from France to Germany, Karl Marx is usually considered as a key contributor to sociology (although he is known as political-economist). His critical studies of human nature, history, and society are still amongst the most cited, read, and taught works in this field, and beyond. Elaborating how and why is society split between economy and politics, Marx not only theorized social relations but practically changed them with the invention of an alternative society. This was his understanding of science as a critical activity, rather than mere descriptive and informative. His works are varied and numerous, but the first volume of Capital (1867) is still one of the most influential sociological studies, both methodologically and empirically (here is a link to Volume 1 of this work).
5. Max Weber
Next, and still in Germany, there is Max Weber. Seeking to ground sociological research on hermeneutics, Weber's contributions are diverse as they are profound. His work The Protestant Ethic and the Spirit of Capitalism(1904) is maybe the clearest example of how sociology is done rigorously. Weber's work spans from late antiquity to modern times, and his methodological insights are indispensable. For example, in his The Theory of Social and Economic Organization(1915) he describes fundamental notions like the "Ideal Types" of social action, authority, rationality, bureaucracy, etc. Based on these types, Weber was able to describe the deep meanings of our social existence.
6. Georg Simmel
Somewhat from a different perspective, Georg Simmel is another major contributor to modern sociology. His works take a more formalistic approach, opposed to the interpretive one hailed by Weber. Using concepts as Dyad and Triad his attempt was to develop a social geometry. And with the notion of 'distance' he explained how different social formations bring about varied social relations, which then determine our behaviour. His famous works are On Social Differentiation (1890), The Philosophy of Money(1900), Sociology: inquiries into the construction of social forms (1908), and Fundamental Questions of Sociology (1917).
7. W.E.B. Du Bois
Moving on to the U.S., one might think of Parsons as the leading American sociologist. However, and although the latter had had a major impact on American sociology, more interesting thinkers are Du Bois and Goffman. The former, W.E.B. Du Bois, has contributed a lot to our understanding of race and racial issues as fundamental to sociology. In his 1903 The Souls of Black Folk, he conceptualized how 'double consciousness' is formed among race-discriminated people. His concept of 'the veil' resonates with the mask that subordinated races put on themselves, and how it shapes their interactions with others.
Pictured: W.E.B. Du Bois
8. Erving Goffman
Still in the U.S. yet much later, Erving Goffman is perhaps the most insightful American sociologist. Based in Chicago, he developed the theory of dramaturgy which focuses on the social construction of the self and its different institutional relations. His classic work is The Presentation of Self in Everyday Life (1959), where it is argued that agents are acting themselves in different roles, stages, plays, narratives, and other social conditions. Consequently, the Self is thought of through the lens of symbolic interaction, as it is dependent on time, place, and audience. This is done via impression management, defining the situation and following concepts. Thus, people adapt to cultural norms and values so to be a part of society. When they choose otherwise, stigmatization of deviation occurs. This was studied later with relation to mental health in his 1961 Asylums: Essays on the Social Situation of Mental Patients and Other Inmates, where the term 'total institutions' was used. Goffman's innovative methodology is ultimately presented in Frame Analysis: An Essay on the Organization of Experience (1974).
9. Pierre Bourdieu
Moving on the contemporary France, Pierre Bourdieu is the most renowned sociologist these days. He tried to systematize and synthesize all previous approaches in a coherent and complicated sociological theory of practice. His major concepts are Habitus, Field, Doxa, and symbolic violence. By differentiating types of capital, his works has made a great impact on our understanding of sex and gender relations, educational and economic reproduction, aesthetic judgments and distinctions, intellectual positions, etc. Without Bourdieu, contemporary sociology would not have been what it is today. Among his numerous works we find Distinction: A Social Critique of the Judgment of Taste (1984) (see the introduction to this work here), Reproduction in Education, Society and Culture (1990), Language and Symbolic Power (1991), The Masculine Domination (1998).
10. Bruno Latour
Like Durkheim and Tarde a century before them, Bourdieu and Latour also had a complicated relationship. Bruno Latour tried to avoid some of the pitfalls of Bourdieu's edifice. Latour's work is more in-sync with science and technology, as well as their effects on human life. He developed a sociological method called Actor-Network Theory, with which he studied both the general and the very specific domains of our societies. In his early works, Laboratory Life: The Construction of Scientific Facts (1979) and Science In Action: How to Follow Scientists and Engineers through Society (1987), he deals with methodological issues of social science. Later, in We Have Never Been Modern (1993) he studied and redefined our understanding of our(selves as) modern societies. These works later culminated in his 'textbook' Reassembling the Social(2005), and the more elaborated Inquiry Into Modes of Existence: An Anthropology of the Moderns(2013).
Pictured: Bruno Latour
This list is far from being exhaustive. Incredibly important social thinkers were left out so to make it a top-10 list. However, one should not forget the fascinating insights of Theodor Adorno, Jurgen Habermas, Zygmunt Baumann, and others. These are all people who made sociology worthy of its name. All in all, sociology is a diverse field of research with different approaches to society and the social. It utilizes many conceptual and empirical tools in enquiring our common and shared existence, along with its risks and opportunities.