"the speedrunning community" is far too vast unfortunately to pick out a specific few runs. I know what the great OOT/MM runs are. I can link you to some sick Goldeneye/Perfect Dark/Mario Kart 64 single level runs. But as for "what are the best speedrunning WRs?" there really isn't consensus (mainly because of how different each game is.)
That being said of course Sig's 1:44:01 120star is pretty sick, as are all of his 1:44:XXs. I'm not sure how many people have even subbed 1:50 so 1:44 is pretty insane.
I don't think he preserved vids of his 1:44s (beyond his first one on Sept 1) because he hated errors in them and wanted 1:43. Failure to preserve WR runs is common among speedrunners and is very annoying and stupid.
http://www.youtube.com/watch?v=lXk8eR4FoQw
That's the 1:44:52 he did after streaming 12 hours every day in August (finally achieved on Sept 1 lol.)
WR is 1:44:01 so it makes watching that run irrelevant, but whatever.
People should note that SDA is not a WRs site. It simply hosts good quality fast runs of games. So don't take everything you see on SDA as the WR. Some are, most aren't.