I agree with Pace's assessment. Having flown the B55, E55 and the 58, I thought the longer 58 was the nicest flying one and the most practical. It is also the only one available with flight into known icing certification.
But, these aircraft are expensive to operate and maintain so do your homework on what it will cost you to own and operate one including insurance. A fellow I know that upgraded from a P model Bonanza (260 hp) to a B55 Baron (2 X 260hp) found his all in cost per flight hour flown over 5 years was almost triple that of the Bonanza. Much higher insurance, the need to get a bigger hangar, more recurrent training, and doubling the engine/prop overhaul costs add up fast. He also found that his average true airspeed was only about 10 % higher then the Bonanza. However for him the safety benefits of the second engine and the much stronger climb were worth it.
IN any case there are lots for sale so buy the best one you can find it will be the cheapest to own in the long run.