If we talk about 80/90, it's clear that the band with the best B-sides is U2...there's no doubt: walk to the water, luminous times, spanish eyes, sweetest thing, deep in the heart, love comes tumbling, a room at the heartbreack hotel...who other?
(maybe just the Boss has written a lot of songs not for lp, see "tracks"...).
But if we talk about post 1990, then u2 fade away, unfortunately...I can't remember a lot of songs worth to be mentioned: maybe two shots of happy; yes, there are some good covers (I like fortunate son, paint it black, satellite of love and night and day from red, hot & blue), but there's no race (IMO) against Oasis'masterplan.