YYZ - Toronto is excellent
Seconded. They're great. I get scolded sometimes for doing dumb stuff (super late check in) but it's always my fault and they're always good about it. ;-)
BUF has an incredible crew too; in IRROPS, I'd rather be in BUF flying DL than anywhere else in the system.
SFO is pretty good too, especially the evening crew.
Checkin/gate agents yes. SkyClub absolutely not. My least favorite club in the system due to staff.