Evolution Worlds and Custom Robo, both for Gamecube.
Evolution Worlds was a turn-based Japanese-y RPG, and I haven't played it in years, and I've never heard anyone talk about it ever. I was pretty young when I played it, and I usually rented it and only got to second dungeon most of the time. Eventually I bought it and got to the final dungeon, but never bothered to beat it for some reason. I'm pretty sure I still have it lying around somewhere, so I'll probably replay it eventually.
Custom Robo was one of my favorite Gamecube games that no one I know seems to remember. I rented it a lot when I was younger, but never bought it for some strange reason. I remember I used to make up my own themed sets for robos, like a "Freeze Tag" set using one of the faster Robos to just run around and freeze people. I really want to play it again now, but I can't find it online for a reasonable price...