You are taking it to extreme and every soultion taken to extreme is bad. I could do the same with bosses that doesn't have any gimmick. Great example would be a drug lord from the first Hitman. You just have to stand in front of him and put few mags of ammo into his head. It's funny to see cut-scenes when he talk and you can barely see his face because he has so many bullet holes in it, but that's all fun that you can find during this boss.

Can't think of very many...
I remember liking the endings of Call of Duty and United Offensive. They didn't change the gameplay, they didn't get ridiculously difficult, there was no boss fight. They were just really huge, epic, intense battles. Good endings to good games.
Call of Duty 2 was a bit anti-climactic, I thought. The previous 2 levels were these huge epic fights to take and defend a towering hill. Then the final level was just clearing out another town, which I had already done at least a dozen times in the game.
Call of Duty 4 ended with... Another truck chase. Which I always thought were by far the worst parts of the series.

Hmm... HL2: Episode 2 was pretty fun. Really epic battle in a pretty big arena. I really enjoyed the combination of driving, using the gravity gun, and shooting.

Fortix 2 ended well. It basically puts everything from the entire game into one level, and adds a big boss. It is difficult, but not "die 50 times" difficult. As long as you had played the entire game, you will have gradually learned everything there is to know, and can beat the final level without much of a problem.

Deus Ex: Human Revolution: The Missing Link was nice. But maybe that is just because I am comparing it to the crappy boss fights and horrible ending of the base game.

How could I forget it: the ending of the first Halo!

I really love that ending, racing to safety while the world crumbles around you. You could say it deviated a lot from the gameplay before that, and it wasn't even a boss fight, but a race to survival.

That end level was 100% pure fun and excitement to me, and I didn't even mind having to replay it several time from the start before finally making it. In fact, even after finishing it, I replayed the ending many more times, just because I enjoyed it so much.

Halo 2 ending level had much more suckage, but it was made a bit interesting by the fact that with some perseverance, you were able to fool the game and smuggle a flying Banshee vehicle to the ending level, something that the game designers were not expecting you to be able to do. You actually had to shoot the Banshee's wings off before you were able to push it through the narrow corridors to the end level.

Oh, the satisfaction of fooling the game designers like that, and being able to shoot the annoying enemies in the last levels from high above with your Banshee. :)

Half-Life 2 was an epic example.

And honestly timppu your puzzle boss ending is exactly the kind of thing that pisses me off. I just played a straight-up shooter for eight hours, I'm ready to move on and play something else, and here's this multi-phase puzzle ending. Fuck that shit.

That was on my wishlist if it was ever available DRM free. Not so tempted now.

Worst ending for me was Fallout 3. Best was PS Torment > not for the cut-scene, just for a satisfying completion to a wonderful story.

It's kind of funny.
I know I'm wearing my nostalgia glasses, but thinking back on KOTOR I actually remember that bossfight kind of fondly.
It sorta reminded me of some old (S)NES boss fights.

You also made me realize that I haven't been playing too many games with endings lately.

Mark Of The Ninja's was done decently well for being a pick your fate type.
It keeps the core gameplay going until you reach the fitting end.

Oh please. The first time I fought Malak, I was a light-side dual-wielding scoundrel-councillor who acted as stun-support for the party. For that one fight I had to pump myself full of stims (that I'd never used previously), ditch my armour for a robe, and switch to a single lightsaber, all just to get enough attack rating to have a 50/50 shot at hitting him. Also, I had no way of taking out his health recharges, and one of my best crystals had to stay on the sabre I'd ditched.

Guess why I still remember that fight :P

I can see why. Taking LSD, putting on a dressing gown and picking up a glowy stick (the LSD's kicked in) is no fit way to return to a game

Don't knock it till you've tried it XD

Yeah, it's funny how the whole game is super easy and you can ignore half the mechanics... until the final fight. Then all of a sudden you have to learn all these nuances and use all these items to have half a chance. I had to pump myself full of drugs too, and finally use my consular powers.

Divinity 2 DKS - especially after the really disappointing Ego Draconis ending.

I loved the end of KOTOR. :o

Well it sometimes is I mean I sometimes miss big climactic final boss battles with an amazing score in RPGs and games in general these days especially how awesome these were:

http://www.youtube.com/watch?feature=player_detailpage&v=GG5ELlPZFGI&t=141

http://www.youtube.com/watch?feature=player_detailpage&v=Xx-oNUud0Qk&t=470

Spec Ops - the line.

The end boss is a tough call to make: kill that son of a bitch, or force him live his hellish existence.

Maybe I misunderstood you. I wasn't sure what was your original complaint, e.g. the end fights that are 10x harder than anything before, ie. making finishing the game very hard, just due to the end fight? I hate those kind of boss fights too, like the ones in XIII. The "puzzle" fights are usually quite easy, albeit potentially time consuming. Like e.g. the pit monster in Half-life (yeah it was not the end boss, but still, I feel it could have been a good one). Once you understand what you are supposed to do, it isn't that hard to achieve it.

Just today I finished GTA: Vice City. Its last story mission ("Keep your friends close...") wasn't hard at all, and also didn't deviate from the rest of the game in gameplay. So is that the kind of ending you prefer? I OTOH found that last mission kind of a letdown. Too simple, too easy, too anything but a memorable ending to a decent game. I just stood there at one spot shooting anything that moved for a minute or two, and poof, end of the game.

Of course, if I am playing e.g. a tactical game, I don't wish the end boss fight to be e.g. a pure action sequence, because I didn't want to play an action game. That used to be quite common complaint with many classic point&click adventure games, when they quite often had some simple but forced arcade action sequence, while rest of the game was pure adventure gaming. I can understand that complaint.