I think it's time for an old Doctor again. I vote John Hurt or Bill Nighy.
One suggestion I'd heard which sounds interesting to me is Captain Jack inadvertantly interfering with the Doctor's regeneration, regenerating him into... John Barrowman! (I can only imagine their first scene together. The Doctor having to be especially firm about rejecting Jack's sexual advances. The Doctor looking in the mirror for the first time, "What?!?"
)
The funny thing is, I've sometimes thought that David Tennant is probably the only other actor in the world who could conceivably play Rimmer.
One suggestion I'd heard which sounds interesting to me is Captain Jack inadvertantly interfering with the Doctor's regeneration, regenerating him into... John Barrowman! (I can only imagine their first scene together. The Doctor having to be especially firm about rejecting Jack's sexual advances. The Doctor looking in the mirror for the first time, "What?!?"

I think Chris Barrie might make a good Doctor. (Rimmer from Red Dwarf.)
The funny thing is, I've sometimes thought that David Tennant is probably the only other actor in the world who could conceivably play Rimmer.
