Arkham Horror 2e. It's a big, lumbering behemoth that takes up all your table space and has a whole load of rules jank... and that's all part of what makes it special.
We once made all of our friends run in fear (and there was nowhere to go since we were at a vacation rental), just by setting this up. They made us put it away.
I think the closest I'd get is Dark Void, which is a lot of serviceable corridor cover shooting before three or so levels where you have the jetpack, you're going from on the ground to flying around to getting your hovers just right, and it's action unlike anything before or since.
Blueshift.
Doesn’t innovate at all. Nothing new mechanically and the HD textures and models kinda suck, but I just love not only seeing the perspective from Barney and knowing what he experienced prior to HL2, but also, it's somehow more imersive than the original because of how dull it starts off.
Seventh Cross: Evolution on the Dreamcast was a launch title with an inexplicable DNA system, crabs that mercilessly ate your starter amoeba form, cheesy combat and a very weird hidden FMV ending involving goofy cavemen.
And yet... it was amusing.
Breath of fire dragon quarter is one of my favorite games of all time despite the fact that it's the weirdest entry and arguably what killed the franchise
Battletoads has lived deep within my psyche for 34 years now. Is it difficult? Of course it is! I still haven't beat the Hypnoball, let alone the Dark Queen. However, the variety of levels, the music, and the graphics are all living in my brain.
Ninja Theory's 'DMC: Devil May Cry. Best title in the series, hands down. Kick ass soundtrack, smooth, responsive combat...A Dante who was an actual character, where previously he alternated between RE reject and TMNT.