What about Metal Bane Solid: Big Guys of the World?
It was overhyped in the beginning, but after the leaked footage everyone really stopped caring about it, and most players made fun of the game.
I'm not going to say it was my favorite, but I really did like it alot. It seems that everyone gives it a lot more hate than required, just because it didn't live up fully to the hype, and the graphics were often criticized, as well. Some fans pretend it doesn't exist because they were so dissapointed with it. It had one of the best storylines out of the series, but the characters were certainly the best out of all the games, and the soundtrack was great, too.
My favorite will always be Metal Bane 2: Solid CIA, though. The characters were almost as good as Big Guys of the World, even the soundtrack wasn't that good. The gameplay was great, but the story was what really set it apart. It had, undeniably, the best story line among the series, it made me cry, laugh, and ejaculate more times than I could count. It also had great graphics for its time.
Metal Bane Mobile: Hothead Invasion was just an insult to the series. Even though it is one of the most-played games of them all, it still sucks, and just isn't true to what the series stands for.