I think the first on my list would have to be Blood II. It was the first game I owned on GOG.com, and by far the most universally-panned. I only played it for a short while, and even then I hadn't played the original. Still, it had some fun to it. I loved the b-movie (or should I say b-game?) influence and the cheesy retro graphics. It didn't run in 32-bit, but had enough blood and guns to keep me interested for what I would like to call 3-or-so hours every time I installed, upon which I would forget about it and uninstall it again.
The second game I would like to suggest you play pronto is E.Y.E. Divine Cybermancy. I've played Deus Ex. I bought this, expecting it to be a poor-man's Deus Ex Human Revolution. In all honesty, I've played this gem of a game way longer than DXHR for one good reason: The violence. Nothing about the game makes any sense. The story is garbage, they all talk in a made-up language, but good lord the ACTION of the game is by far a crowning achievement. With save editors, you can boost your character's skills to max, allowing one to practically telefrag anyone, anywhere, at any time, with the "Dragon" skill, and blast people to smithereens with the giant hammer thing. I've never played much of the campaign, I would suggest buying it for the random mission mode. It's by far the oddest game I've ever played, but what it does right it does exceptionally well.
Another game I'd recommend to anybody is Chaser. It has lots of very strange missions, wonky levels at times, and its fair share of terrible voice acting, but the game has a heart to it right out of one of those 90's alt-sci-fi action movies where you felt more like you were reliving someone's life rather than actually watching moving pictures. The game's quite long, and doesn't have just one story arc, but almost limitless ones, at least 5 lengthy levels per the three-or-so arcs I went through, followed by a wonderful sniper mission and a very confusing underwater maze paced with sunken ships and floating gold dots out of nowhere.
Sometimes the games that are the most fun have less than 60 metacritic scores. I'll list some such games here: The Haunted: Hell's reach. (I simply adore the black baptist, shouting homilies as he blasts hellspawn to bits!) Red Faction: Armageddon. (Magnet gun, anyone?) Iron Grip: Warlord (By far, the saddest co-op failure i've seen. The game's a blast to play.) Medal of Honor: 2010 (the game with two engines. Each of them fun to play.) Necrovison (a world war one zombie/vampire shooter based off the painkiller engine) Postal 2 AWP and 500 weapons (by far the best way to play) and more. All of these games I love, all of them I've spent hours playing regardless of how panned or trashed they were. I've had more fun with games that have recieved mediocre reviews than those that recieved Game of the Year versions. If anything, this article should show you, dear reader, stumbling onto my page off of google, that Metacritic isn't all it's cracked up to be. Sometimes a broken game simply has a broken heart. It could be fun if you keep at it, and if you know where to look!