The Tyranid Lictor, and especially Deathleaper
….no, i’m not just trolling with an intentionally bad unit, i swear :P
I started 40k with 2nd edition (or, rather, just as it was ending…), and fell in love with the 2nd ed model of the Lictor. I never got to use its rules, but when 3rd ed rolled around I loved using them despite their relative ineffectiveness. They’ve sorta been slowly de-powered through each new edition, but I love the concept of the unit, and I’ve owned one for every new edition.
Then Deathleaper showed up in the Rise of the Swarm campaign up in Canada, and then became canonized with an entry in the 5th and 6th ed codexes, and while many don’t like him, I think he’s a brilliant choice to both the background and the game, and his model is absolutely fantastic!