Off the main Wiesn site, many go to the
Kultfabrik or
Optimolwerk near Ostbahnhof as it's a huge party area with tons of bars and clubs open all night. Get a taxi.
Hacker-Pschorr at Theresienhöhe is staggering distance from the Wiesn and is thus very popular, often with people who didn't get into a tent. Likewise,
Wiesnzelt at Stiglmaierplatz (further away, but still a choice for those who didn't get in).
Schrannenhalle Wiesn-Nächte near Marienplatz is very central and also popular - so much that they are doing ticketing this year!
M-Park and
Nachtgalarie (NAGA) both on Landsbergerstr. attract a young crowd.
Backstage is more for the indie & rock kids.
For football,
Ned's/Kilian's,
Molly's and
Outland - all are relatively near S-Bahn stations so will be busy.
If you are in the middle of a Wiesn depression, Lamm's at Sendlinger Tor will be just the ticket as it will suit your mood and it never stops serving.
Wiesn-Portal has a good list, including some of the more glamourous places (Lenbach, The Garden, 8 Seasons...), the ones I've listed are more likely to let in someone who is slightly rat-arsed.