On the aesthetics front, I have slowly migrated to a handful of groups: DA 7400 STI, 600 6400 STI, and late 1980s Superbe Pro. On the MTB front, I really like the late 1980s/early 1990s Deore XT.
The stuff that does not fall into these groups tends to get sold off. So its not so much a matter of what parts I currently have. Parts in hand can be converted into the group of my choice pretty easily.
I am not a fan of the 6500 group.