C310 or Baron for the speed/range/payload.
Why turbo? You can fly C310s and Barons into the Flight Levels on long trips. Used to fly a non-turbo 310 regularly up to FL180 on survey work.
Having flown around 15 different 'twins' from Cessna, Piper (yes Seneca 1 & 2), Aerocommander, Beechcraft & BrittenNorman, (no turboprops unfortunately), I found they all had their positives & negatives, depending on what you are using them for.
All comes down to the 'mission' and the costs I guess.
Queenair, C310 & Baron were my favourites.