Moraff's world. though some might say Moraff's DOTU is more ermm... challenging?
https://www.youtube.com/watch?v=gou42MyAvuE

I never got to play Encounters, but it's on my list to pick up since I got a PS2 again.

Zeonic Front however ermmm, I never got past mission where you have to find White Base.

I got stuck on that one HAHA it's with the rick doms in the underground caves I think

but yeah old school gundams was fun but shitty fun <3

Duke Nukem Forever
Omerta - City of Gangsters (now that the GOG version can actually be finished properly)
Fahrenheit / Indigo Prophecy

Not super great games, but pretty decent.

Virtua Racing on the Sega Saturn

Rushed, published by Time Warner and not Sega, terrible engine sounds, and framerate drops and slowdown. The reason I love it: exceptional controls and gameplay, and a ton more cars and tracks than any other version of Virtua Racing. It sucks at being the arcade but is good at being a racing game.

Jagged Alliance - Back in Action: most reviews for the game were meh, but games of that kind are really rare games nowdays, good tactics +RPG elements. Don't think it's a sequel to old good JA series - just play it like standalone strategy game.

Two World 2: I've really enjoyed it's world and atmosphere, dark scary dungeons and mystical beasts around, game could engage you for dozens of hours, but RPG system was rather simple and NPC's are just so boring.

Oh yeah I should have put Two World 2 on my list too. The storyline and characters were your regular Fantasy-stuff but the gameplay was fun.
To quote the OP's initial text:
'It is a Third person Coop based game. I enjoyed playing it With my friend, but most reviews and comments of it were abyssmal.' (bold text is my edit).
In other words: media thought the game was bad, the OP didn't.

I used the same reasoning for my inclusion of DMMM; media did not particularly like it, most vocal gamers certainly did not like it,...but I did like it.

It seems the reviews were far more positive than I recall from the time:

Gamespot: 6.7/10
IGN: 7/10
Eurogamer: 8/10
1UP: D+
Gamezone: 7/10
Gametrailers: 8.1/10
Gamereactor: 7/10
VideoGamer: 7/10
ImpulseGamer: 8.7/10
gamesxtreme: 8/10

The average is around 7.5/10 which is not terrible at all.
I must have confused it with the console version, Elements, which averages around 5/10. Oh well, my bad.

Interesting to note that games rated 7/10 were still considered 'good' or 'fair' back then, today a game is seen [by the mainstream] as terrible if its anything below 8/10.

I had to think long and hard to come up with examples:

DarkStar One
It looks nice, but it's really repetitive, lukewarm story, unlikeable characters... It's not really "terrible" but really not a good game either. Still I finished it. Don't even know why I wasted that much time on it...

Rise of the Triad - Dark War
I know that some people like this game, but I found it utterly silly and laughable. Rather terrible. Still completed it back in the day when first person shooters were my favourite genre. But just because I knew all the other titles inside out at the time.

Deus Ex Invisible War.The definition of this thread.

Might and Magic VIII – not held in a particularly good regard, but I liked M&M7 very much, and the sequel was more of the same, so it was fine by me. They even kept Arcomage.

Black Mirror 1 – some people consider it the worst game in the series, I think it's the best one. Samuel was a much better protagonist than teen-angsty Darren. I even found the voice acting appropriate to the setting, and every reviewer slammed voice actors in that game.

Redline – not a very well-known game around here, IIRC it uses an old Quake engine, which may be good for indoor environments, but makes outdoor maps look terrible. Characters and vehicle controls are wonky, but the ability to switch from vehicle combat to classical FPS on foot was quite revolutionary at the time. The missions are quite fun.

Dishonored is brilliant. But doesn't cut it as a Messiah of M&Ms substitute. Maybe if the people of Dunwall considered spikes as a means of decoration...

I love Dishnored.

I just want a kickass first person hack and slash. Kingdom Come Deliverance has me hoping!

no comments, since i'm still busy with playing all the terrible "best" games :)

well, if you compare it to modern shooters or modern wrpgs, with rail-roaded plot progression, shallow dumbed-down game-mechanics and more GREY BROWN BLOOOOM!!!! ... it's a fucking under-rated work of art.