The
Ted Smith Aerostar is the fastest production piston twin, however it can only carry 6 people, has limited payload and range.
The
Beechcraft B60 Duke has slightly more payload and range, but is slower and is a gas guzzler.
The
Cessna 421 has much better payload and range, but has expesive to overhaul, geared engines.
The
Piper Navajo is slightly slower than the 421, but has counter-rotating engines, which are safer when the left (port) engine goes out.
(bonus points to whoever can identify the plane in the left of this pic)