With Classic models like the scrambler, this company has done a lot for bmx. The later high end racers like the Sting are very collectible these days. The Sting was the first production bmx frame I know of to have brazed welds. Schwinn has continued to support some great riders as well. I recall Donny Atherton way back, Jay Miron for awhile, and many other greats. WOW, I just found an archive of ALL the Schwinn bikes, check this link:
if you are curious what year your schwinn is, this is the place to look!
Also found this great archive of Mt. bikes and Schwinns