Vintage 30s for me - by far my favourite.
A few years ago I did a side-by-side demo of Marshall 1960A (with G12T75s) & 1960AV (with V30s) cabs. The AV with V30s just sounded far superior to me - much more depth, projection, tone, chunk.
My current cab (Mesa Recto 2x12") has V30s, as do the other cabs I'd like to get (Engl E212VH, Mesa Recto 4x12", H&K VC412A30).
The only other speaker I'd really like to have is the Celestion Classic Lead 80. AFAIK they aren't installed in any production cabs, but I tried them in a VHT Pittbull 2x12 combo in about 1994. That amp sounded unbelievably good :)