I just love my Armed Trader Anaconda the 'Doom Banana'. It does everything I would like except land at outposts.
As Member of the Sidewinder Appreciation Society, I will say
"The Sidewinder Mk.I, of course!"
Courier. Small and agile, and incredibly fast with enough internal space to do whatever I want. (no i'm not a bulk trader) It can also take a real beating and has enough firepower to ruin anyone's day. It also looks nice (come on, where's the ship kit already?).
TBH I am partial to small ships.