Not in the ratings, but in sheer comedy: Last night's oversized Pam Has a Baby episode of NBC's The Office had a million more viewers, but Community had about a million more laughs. ---
So many reasons why: Joel McHale's naked pool-shark prowess, "White Abed," rampant '80s-movie references, lines like "Jeff [McHale] is 10% Dick Van Dyke, 20% Sam Malone, 40% Zach Braff, and 30% Hilary Swank in Boys Don’t Cry," an Urban Outfitters swipe, the random Ernie & Bert closer, this list goes on--"Physical Education" (full ep here) was one jam-packed episode of funny shit. If NBC doesn't renew Community for another season, any good will for killing The Jay Leno Show is eradicated (oh, like you didn't know a Leno jab was going to get in here somehow).
The meta-home run was Abed channeling Mad Men's Don Draper to hit on Annie (Allison Brie--she also plays Trudy on Mad Men, hence the genius here):