I'm going to be honest, if I can only have one ship, it'll be my Anaconda.
I've had the same hull, called either Idamo or GoldenMember (paintjob dependant), since the Xbox GPP back in 2015.
A short list of accomplishments are:
Singlehandedly gave me my triple Elite status.
Earned over a billion credits through NPC genocide vouchers before the combat payment rework. It's now close to 2 billion.
A round trip to Colonia in its 23.6ly combat outfit when the first CGs were happening out there. I got there, did one CG set and came back because I hated it. #BubbleGang4Lyfe.
Landed on Achenar 3, both with me flying and my NPC pilot flipping around for roughly 17 minutes straight. RIP Mr. L. Fitzpatrick, you were a terrific pilot and only slightly crippled by your Onionhead addiction.
But most importantly taught me a valuable lesson in the art of the brave Sir Robin maneuver and screw the costs, have good defences, when I was attacked by a wing of players and my shields and hull were stripped down to 23% in the few seconds it took my FSD to supercruise out. Haven't come close to being ganked since.
Even now, it's still my most used ship and would remain so, magic hull mass or not.