The martial snares and boyish histrionics that made U2 one of the world's biggest rock acts have held up pretty well. Too bad that excepting ''I Will Follow,'' their first two LPs get ignored on the best-of disc The Best of 1980-1990/The B-Sides in favor of songs from The Unforgettable Fire and inexplicably Rattle and Hum. As for disc 2, aside from the playful ''Sweetest Thing'' and some worthy covers, the B sides sound like it. B

