A wizard who is terrified of the dark. He specializes in spells that give off light: lightning, prismatic, daylight, and even some shadow spells. I attempted to play one back in 3rd edition but the game fell apart after a couple sessions.
A more recent character that I have yet to be able to play is a 5e character that is triple multiclassed. Well, ends up that way. It's a gnoll pup raised by a retired paladin. The paladin was part of an adventuring party who were tasked with taking out some gnolls. They tracked the group of gnolls back to their home and attacked. There were babies there, and they were met with the "baby orcs" situation: Do they kill the babies because they will grow up to be evil bastards, or do they spare them and they could grow up to not be evil bastards? The paladin wanted to spare them, the others wanted to kill them. It led to blows and the paladin killed most of her party (one or two fled), but was only able to save one due to a fireball from the wizard before the wizard fled. The paladin retired and she raised the baby gnoll to become a LG paladin herself. The villagers came to accept the gnoll mostly due to their trust of her caretaker, but no one else in the world would extend such feelings.
The gnoll left her home, carrying the old paladin's gear as her own, and joined up with her own adventuring party. As she would gain levels, her race's demonic influence would begin to manifest. Once reaching level 3, she'd gain a level of barbarian for the rage, manifesting as her race's more evil bestial side. She tries to repress it, but certain situations would make her fly into a rage. After a few more levels of paladin, Yeenoghu would take notice of one of his "children" trying to fight against his "gift", and she'd gain a level of fiend warlock (Yeenoghu trying to re-corrupt his wayward child) much to her dislike. From there on, she'd gain a level of paladin and then a level of warlock, alternating (or for every 2 paladin levels, she'd gain a warlock level).
I have never gotten to play this character, as most DMs don't allow nonofficial races, and there's no official gnoll race. Those are the 2 characters that I have wanted to go for. Not the most "optimized" of characters, but that's not what I go for.