Its strange, alot of my all time favorites are underappreciated heres the 3 I think got the worst rap-
1.) Land of the Dead Road to Fiddler's green Xbox (2005) this game got multiple 5 and 6 ratings, but I got it the night it came out and I found it to be a fantastic game, mabey because I'm a serious George A Romero fan, but the game plays just like a Romero movie, even the music and sound fx are classic Romero, and the graphics are pretty impressive. The enemies are a bit repetitive, but hey its the Zombie apocalypse right?
2.) Killing Time 3DO (1995) another one of my all time favorites that no one else knows about, this FPS is lots of fun with a scary but fun atmosphere I just loved everything about it, lots of different enemies ranging from Zombie duck hunters to ghostly house maids to giant beetles. The music is another strong plus for this game, with a mix of eerie music to crazy carnie tunes, it meshes well with the game and creates a great experience, I pray one day either the 3DO or PC version ends up on PSN or XBLN
Silent Hill V Homecoming PS3 (2009) Alot of Silent Hill fans think this game was horrble, I on the contrary find this the best installment since Silent Hill 2. It has a creepy story, though slow in the very begining, I thought it paced well throughout the rest of the game. The music, and overall atmosphere matched up with the first 2 games well with lots of creepy, ominous locals and strange characters to encounter(theres one boss thats a 15 foot tall porcelain doll whos image haunts me till' this day!) and I just thought it was a solid story/play overall.