I don't know if this quite qualifies as a classic, but I will nominate the discontinued ProAc Tablette 50 Signature. I own a pair of these tiny gems, and if fed with a good upstream signal they sing loud and gloriously. For such little speakers they exude a very large soundstage and presence. If I ever do decide to upgrade, it'll be to the soon to be classis ProAc Response one SC. Oh, and yes, I think the ADS 2002s were pretty darn cool in their day. It would be neat to have a pair of those.