Knight has always been my favorite class, though lacking in many miscellanous skills he is an extreme fighting machine.Troll would also be a nice choice because of GM BodyBuilding and Regeneration but I emphasize offence over defence so a Knight with GM Armsmaster along with Master BB and GM Plater is my top choice.
I am also thinking about a solo Dark Elf, since her promo is dead easy for me now and she is the best Jack of all trades in the game...although considerably lacking in hp but with two good swords I think she could stand up to some close malee combat. (disarm, merchant, tp, fly, invisibility - but only Expert Armsmaster and no bb)
BTW, I would like to ask your opinion on a solo Dark Elf.