First choice: Definitely the original NCC-1701. No bloody A, B, C, D or E. The ship may be a bit cramped, but there are plenty of planetary missions and shore leaves. And Captain Kirk is DA MAN!
Oh, and don't forget the women in miniskirts. Yeah, silly and impractical, but what can I say? I'm a leg man.
Last choice: Of the Enterprises
I'm familiar with, the 1701-D. I'd find the people boring and I never liked the ship.