My favorite is the T-10, followed closely by the Challenger.
The T-10 has high capacity autoloading multicannons with either 5 efficient gimballed beams or two small LR plasma slug rails, dual efficient thermal vent turrets and a high capacity corrosive multi on the other hardpoints. In most other aspects it may be worse than my Conda, but once those multies start hitting hulls, oh boy is it glorious. Even more so than a full multi FGS.
The Challenger is currently tied with the Krait as my favorite medium pad combat ship, (both possibly slipping to second thanks to the FGS I'm testing) and is equipped with triple medium PAs and quad beams on the other hardpoints. Thanks to GSRPs it's got a 900mj biweave, with +56%resists and a 6A SCB, while still having over 2K hull when a fuel scoop is fitted.
I used to fly a Chieftain, but IMO the Challenger outclasses it in every department except top speeds and has been designated to module storage.
I bought a Crusader when it was released, flew it for a few minutes then docked and sold it. The Chieftain and Challenger are both better ships, with the Krait and FGS cementing it's mediocrity due to both being able to launch two fighters without sacrificing shield strength while also having better firepower, jumprange, multirole capabilities and looks.