2. Sonic Adventure 2. Despite the hate that the 3D Sonics get, this game is still almost perfect. A wide variety of missions even in the main game, and unlike many, i enjoyed the running, treasure-hunting, and mech segments equally (only part i didn't like was the kart racing). Add on four extra missions for each stage, boss rush mode, and an entire virtual pet game on top of all that. Add in a rockin' soundtrack and solid story, and you have something truly awesome.
What always made this game stand out in my mind is the final reward: a truly fitting re-rendition of the Green Hill Zone, something to really strive for and something i wish all other games had: a real reward for 100% completion beyond a mere pat on the back (or less, in the case of some games).
Monster Hunter: pissing me off since 2010.
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