I've both run and played one-shot games with AD&D (1980s version) and GURPS (3rd Ed., but 4th works just as well), and have played in one-shots using Hero System, Delta Green, and others that usually aren't seen as one-shot. In my opinion, the disadvantage of games like D&D and GURPS for one-shots is that one-shots are often used to introduce new players to RPG play, and as such, a large, complex game system isn't the best choice.
A simpler game like Risus (full core rules take six pages and can be shrink-printed on a single page, full-out character sheet takes one side of a 3x5 index card) works better for this kind of introductory game, because someone unfamiliar with the system can pick up enough to enjoy it during character creation -- and have as much fun as an experienced player. While GURPS or Hero System can be tuned down enough to do this, it takes an experienced GM to know what to leave out without (for instance) making combat too deadly or taking the intensity out of the game -- thus killing the fun for people who are likely to judge all RPG play by this first experience.
My own preference for one-shots is now Risus -- it works enough like traditional RPGs, even including rules for character advancement if GM and players want to play a longer campaign, to convey a sense of how play proceeds, but is simple enough to learn while creating a character, which takes ten to fifteen minutes.