The foremost exponent of the Vedanta was Sankara. He really was an avatar of God.
In just 32 years of his young life, he wrote wonderful commentaries on many aspects of the Vedanta, especially the Brahmasutra and also various other works.
He was solely responsible for reviving the Sanathan Dharma which had fallen into rapid decline due to the spread of Buddhism.
In those times(around 500 BC) he traveled the length and breadth of Bharat mostly by foot.
He established Muttas (monasteries) in the North, South, East and West of Bharat.
All this was done before his death at 32.
In fact Charles Johnston said:
By the Vedanta, we mean, I think, the sum of the rivers of wisdom which rise in the Upanishads, and flow through books like the Bhagavad Gita into the reservoir of the Brahmasutra, made level and water-tight by the commentary of Sankaracharya.
For an excellent overview of Sankara, read this article by Dev Sharma:
Who is the greatest person whose contribution Bharat has forgotten?
A good online resource of Sankara’s works — www.shankaracharya.org
His most famous hymns:
Nirvana Shatakam (with lyrics)
Nirvana Shatakam (with lyrics Smitha Rao Bellur)
Nirvana Shatakam (Isha Chant)
The Nirvana Shatakam and Bhaja Govindam are considered Sankara’s most profound works.
Param Vedanta has put up an excellent detailed explanation of the Bhaja Govindam. You can also write to them to give you PDFs of each of the 4 youtube videos.
List of Sankara’s Works
Bhashya Grantha (commentaries):
1. Brahma Sutras
2. Isavasya Upanishad
3. Kena Upanishad
4. Katha Upanishad
5. Prasna Upanishad
6. Mundaka Upanishad
7. Mandukya Upanishad
8. Mandukya Karida
9. Aitareya Upanishad
10. Taittiriya Upanishad
11. Chandogya Upanishad
12. Brihad Aranyaka Upanishad
13. Sree Nrisimha Taapaneeya Upanishad
14. Sreemad Bhagawad Geeta
15. Sree Vishnu Sahasranama
16. Sanat Sujateeyam
17. Lalita Tri-satee
18. Hastaamalakeeyam
Prakarana Granthas (philosophical works):
19. Viveka Chudamani
20. Aparokshanubhooti
21. Upadesa Sahasri
22. Vaakya Vritti
23. Swaatma Niroopanam
24. Atma-bodha
25. Sarva Vedanta Sara Samgraha
26. Prabodha Sudhakaram
27. Swaatma Prakasika
28. Advaita anubhooti
29. Brahma anuchintanam
30. Prashnouttara Ratnamaalika
31. Sadachara anusandhanam
32. Yaga Taravali
33. Anatmasree Vigarhanam
34. Swaroopa anusandhanam
35. Pancheekaranam
36. Tattwa bodha
37. Prouda anubhooti
38. Brahma Jnanavali
39. Laghu Vakyavritti
40. Bhaja Govindam
41. Prapancha Saaram
42. Sri Ganesa Pancharatnam
43. Ganesa Bhujangam
44. Subrahmanya Bhujangam
45. Siva Bhujangam
46. Devi Bhujangam
47. Bhavani Bhujangam
48. Sree Rama Bhujangam
49. Vishnu Bhujangam
50. Sarada Bhujangam
51. Sivananda Lahari
52. Soundarya Lahari
53. Ananda Lahari
54. Sivapaadaadi kesaanta varnana
55. Siva kesaadi padaanta varnana
56. Sree Vishnu-paadaadi-kesanta
57. Uma maheswara Stotram
58. Tripurasundari Vedapada Stotram
59. Tripurasundari Manasapooja
60. Tripurasundari Ashtakam
61. Devi shashti upachara-pooja
62. Mantra matruka Pushpamaala
63. Kanakadhara Stotram
64. Annapoorna Stotram
65. Ardhanareshwara Stotram
66. Bhramanaamba Ashtakam
67. Meenakshi Stotram
68. Meenakshi Pancharatnam
69. Gouri Dasakam
70. Navaratna Malika
71. Kalyana Vrishtistavam
72. Lalitha Pancharatnam
73. Maaya Panchakam
74. Suvarna Mala Stuti
75. Dasa Sloki
76. Veda Sara Siva Stotram
77. Siva Panchaakshara Stotram
78. Sivaaparadha Kshamapana
79. Dakshinamoorthy Ashtakam
80. Dakshinamoorthy Varnamala
81. Mrutyunjaya Manasa Pooja Stotram
82. Siva Namavali Ashtakam
83. Kaala Bhairava Ashtakam
84. Shatpadee Stotram
85. Siva Panchakshara Nakshatra Mala
86. Dwadasa Ling Stotram
87. Kasi Panchakam
88. Hanumat Pancharatnam
89. Lakshmi-Nrisimha Pancharatnam
90. Lakshmi-Nrisimha Karunarasa Stotram
91. Panduranga Ashtakam
92. Achyuta Ashtakam
93. Sree Krishna Ashtakam
94. Hari Stuti
95. Govinda Ashtakam
96. Bhagavat Manasa Pooja
97. Praata Smarana Stotram
98. Jagannatha Ashtakam
99. Guruvashtakam
100. Narmada Ashtakam
101. Yamuna Ashtakam
102. Ganga Ashtakam
103. Manikarnika Ashtakam
104. Nirguna Manasa Pooja
105. Eka Sloki
106. Yati Panchakam
107. Jeevan Mukta Ananda Lahari
108. Dhanya Ashtakam
109. Upadesa (Sadhna) Panchakam
110. Sata Sloki
111. Maneesha Panchakam
112. Advaita Pancharatnam
113. Nirvana Shatakam
114. Devyaparadhakshamapana Stotram