I mentioned Sonic Battle in the Sonic thread a while back too. It's really too bad that Sega didn't bother making a sequel for that one.
Speaking of sequels, I guess I'll give a shoutout here to Metroid Prime 2: Echoes. Yeah, it was rated highly, but the word-of-mouth can get pretty negative. Most people I know were extremely frustrated with the game, and most of my friends even skipped over it entirely. I can definitely understand where they're coming from, but I'd still consider it one of my favorite games in the Metroid series.
In Echoes, I just loved how Retro finally put Samus in totally unfamiliar territory, away from Chozo artifacts, and gave us something that felt genuinely new. They also managed to develop a meaningful conflict where the Space Pirates weren't even a major threat. The Ing really got under your skin, and by the end, taking on their Emperor felt almost as satisfying as fighting Mother Brain herself. You also got the totally badass Light Suit, which I'd pick over the Fusion Suit any day!