My necro from EQ1. I made her damn near twenty years ago, named her after an old D&D character, she was the first EQ character I ever put real time into, and I still hop onto EQ every few months to fart around on her. Real memories with that character, but my absolute favorite thing to do was sit on the newbie log feeding low levels Blackened Tier'Dal and handing out buffs.
Other than that, my WoW Paladin. I'm one of the only remaining players on my server to have the epic mount achievement, and probably the last on it to have the full Undead Slayer transmog (as in the Naxx release event set). Sure, it was "only" a Judgment recolor, but god was it an amazing recolor. Legion was fun due to that, practically nobody recognized the transmog and there were a couple times I got some major props in the class hall for rolling with a set that was only available for a limited time in vanilla and never since.
Made me feel really good, and reminded me of the days when I had one of the biggest reputations of any paladin on my original server. I used to have this knock-down, drag-out, all-out hatred-level rivalry with the server's grand marshal paladin. He was a trash-tier retnoob who got twinked out by his guild and carried by BG pre-mades all the way to grand marshal, and here I was this dinky little clown suit LC-ranked Zalgradis build who'd been in BG with him on more than enough occasions to know what's up. He was an ass, too, and just about every time we were in the same zone chat turned into a flame war.
Eventually, he got stupid and challenged me to a duel. Probably a good fifty or sixty players showed up to watch me whoop his ass, because all he knew to do was pray for SoC crits, bubble, and heal without pressure.
At the point BC dropped, I had one of the progression guilds on the server helping me get Thunderfury as a thank-you for all the times I helped their members and PuG'ed when they needed a hand. Never did get the binding off Garr, though.