I think, as many people here, I've developed/generated far more characters than I've actually had the opportunity to play. Many end up being useful NPCs here and there (when I'm DMing), but a few that have had the chance to shine in play include:
In keeping with the "first character ever" trend, I think everyone has a soft spot for their first character. For me, that was:
Montor Dragonwing
Human/male
Magic-user
He was begun in B/X, transitioned into AD&D 1e and eventually updated to 2e, finishing at 18th level.
Montor grew and developed through the years as I grew and developed as a player and my understanding of the game. He went from "I cast sleep!" at everything to a more "creative" spellcaster (this was aided greatly during the years when my DM/group allowed us quite a bit of lea-way in spell use/definitions that were not entirely RAW) Using his spells in ways that were unexpected or outside of the strict spell def. became his calling card - using Dimension Door to *bamf* incoming giant-thrown boulders back over the assaulting giants is one classic example.
He amassed a number of unique magic items, a few he actually created himself. Most of these items became retconned into the history and myth of my world setting. He set up a stronghold of his own with a small army of other NPCs (mostly other characters of mine) and followers and carved himself out a nice little realm to call his own in a, then, little-defined campaign world.
He was finally "retired" from play and given a place in NPC-land within the world. He background/story became (as an NPC) that he was the latest in the family line of the "Dragonmage" (the only known mages capable of wielding "Draconic magic" in Orea...acting as "magical defender" of the realms and emissary/champion of the great dragons of the hidden tower of Wyr in the realms of Men)
I think he'll always have a place in my heart simply for nostalgia's sake.
To the other extreme, a character that I had precious little play-time with, but really enjoyed his character and wish I could have developed him more was:
Garap the Bloodhawk
Halfling/male
Fighter/Thief...I don't even recall the levels he was. He was created for a mid-level campaign, so I'm inclined to think he started out around 5th or so and probably didn't make it passed 7th or 8th before the game/group disintegrated.
He was just fun. Full of bravado, an answer/plan for everything and WAY over-estimated his prowess in...just about anything the party encountered...including being quite the ladies' halfling. Ladies of pretty much any/every race. He was slapped in the face at least once in any populated area they visited.
Actually, now that I'm thinking about him, I believe he met his end exploring a suspicious looking cavern (hole in the ground he'd had to be lowered into) that was filled with Rock Trolls. Had to fight a few round on his own because the other bastard PCs were like "We're not comin' down there, what're you nuts?! Climb back up!" Naturally, fending off 4 or 5 trolls at once made climbing rather...impossible. I think the mage finally tossed some spells down to "help" me out.
I can't recall now if he was raised after that or not...that might have been his end...maybe he didn't even finish the game. huh.
Well, anyway, he was fun to play and, as opposed to Montor, a very short-lived character (whether he lived or not. I just mean he was only played for a short time, comparatively speaking)
There are waaaay too many in between to even try to get into. But maybe I'll mull over a couple of more from over the decades that stand out in my foggy memory.
Have fun and happy PCing.
--Steel Dragons