Naxx was a lot of fun. Soloing it, figuring out the fights, the excitement of really accomplishing something when each new boss went down to my two 10-man groups while they were in blues.

Since then the raids are way too frenetic - Blizzard has done some things to the raids to make them more interesting for single-boxers and we multi-boxers can't keep up. I don't think anyone is going to solo Ulduar or ToC10 unless they severely outgear the instnace and don't need any drops. So I think the days of improving your team in raids solo are over.

Pinot, you are right about gear always going by the wayside, but having 20 toons that are geared enough to do the latest raid content is fun. I can join a team, check out the gear the others have, and switch to another toon that can benefit from the drops others already have

It is true that leveling up professions is probably the only thing I'm doing right now that will last for the long tern, but I'm still finding ways to have fun.