Monster Rancher 2, E.V.O Evolution, Harvest moon, Wing Commander 3.
Monster Rancher 2 is #1 for me though. What a great game, #4 was pretty damn good and saw complex idea's that worked well (like an explore map that you actually played in as your monsters and fought wild monsters for exp...but #5 shat the bed. Nobody talks about Monster rancher games though. Turning your favorite games and music cd's into specific moneters you gain experiance, and different moves with. Awesome.
EVO was the original spore, but everyone forgets. THATS how Spore should have been, only more combo's with specific moves depending on the combo you use. Instead, spore had lots of combo's of parts, but none of them made very much of a difference.
Harvest moon...Nobody talks about this, but since snes this franchise has been a cult favorite. Rune factory is a good cousin that also had the same idea but no acclaim.
Wing commander 3 had a good character line up, great graphics, a good branching story and fun space fighting. I could never figure out the last level, but man was it a fun game. Once again, nobody talks about that game.