I have changed my entire fleet so many times, I go back and forth between larger ships and ships I can solo, right now I try and focus on ships I can solo, duo or minimal A.I.
Terrapin
Hornet
Vulcan
Star Runner
Vulture
Leaves some $$ for ground vehicles
I was thinking of going with a Nautilus but the 8 man crew scared me off, same with ships like the 600i, Corsair etc... I know I could run these solo with A.I. I just didn't see the point for now. I wanted a selection of ships I could solo that gives me access to multiple professions and low running cost.