Damn, there were quite a few of "bad" games that I've enjoyed. A few years ago I decided to check out various games by City Interactive (now CI Games) who were widely known for their crappy shovelware shooters and... I enjoyed them. They weren't innovative or anything, they had simplistic mission design, little content and they looked much worse than AAA shooters at the time but... they actually were kinda good. My mind wasn't blown but I wasn't frustrated either, really had a lot of fun. I was expecting unplayable messes but they were actually really solid stuff from what I recall.
And Judge Dredd: Dredd vs Death. I had a crapload of fun with that one, actually. It felt really original in so many ways and was just fun to play. Other than the ending being a letdown and some of the bonus levels being somewhat broken it was a really great and fun shooter IMO.
Then there was a weird twitch shooter called G.O.R.E.: Ultimate Soldier or something. It was very much like Serious Sam despite being a little older and I had a blast playing that one even though I had already played Serious Sam at the time. It wasn't quite as impressive or polished but it was tons of fun.
Then there was Hunter Hunted, a platform game by Dynamix / Sierra. It seemed to be universally panned back in the day and it's quite painful to look at now but holy crap, the time I've put into that one. Finished the singleplayer campaign, the split screen coop campaign and played tons of deathmatch. And
dat soundtrack.
Dat soundtrack! Aaaaand here's a good one: Metro-Police. A game so obscure and universally panned back in the day that nobody seems to remember it. A German open-world action adventure game. Combat sucked, driving sucked, the technical execution sucked but damn, you actually got to interrogate people and solve crimes in an open 3D world... almost 15 years before L.A. Noir.