What do you think are the most influential works in linguistics? Peter Svenonius has compiled a list here of the most cited works, according to Google Scholar. Near the top are general works by Saussure, Sapir, and Jespersen, Lakoff’s work on metaphor, Searle on speech acts, Grice on pragmatics, Halliday on functional linguistics, Brown and Levinson on politeness, and a whole bunch of Chomsky.
Other oldies include works by Jakobson, Greenberg, Quine, Labov, and Lenneberg.
Classics in generative linguistics include Ross’ thesis on islands, Heim’s thesis on indefinites, Abney’s thesis on DP structure, Baker’s book on incorporation, and Pollock’s paper on splitting Infl.
More recent entries (from the 90’s on) include Kayne’s antisymmetry book, Cinque’s 1999 book, Rizzi’s left periphery paper, and several of Chomsky’s Minimalist papers.