how to make the final boss fight satisfying

In the countless missions, tf's and even AE arcs I am rarely satisfied at the end of a mission or arc with the defeat of the boss. I would like to come up with a fairly standard set of rules for how to make the final boss fight satisfying - but not really knowing of satisfying final boss fights it is hard.

Defeating the boss should be the end. Defeating Dr Vahz and then having to defeat cadavers trying to figure out which of the endless horde down below is the magic one to end the TF. So anticlimactic and stupid. Or defeating Romulus and then having to go defeat 300 soldiers. If you want to require other objectives as well don't spawn the boss until the other objectives are done - make the boss guaranteed to end it. And make the boss be all you need - not the boss and clearing the room.

The boss needs to look unique. Worst among Council, but bad in teaming when lots of bosses spawn. Clockwork King and Dr Vahz look unique. FrostFire is hard to pick out even though he is a special boss. Make the bosses truly stand out so we even know we are facing the big bad.

Cutscene before the boss. Very cinematic - a pause that lets you know the boss is there, sets a mood, and makes the final fight seem special.

Little of this helps with generic missions. You can't have a unique boss in every radio mission (although it would be cool, and you have unique characters in almost every Tip mission which adds a lot). You can't do a cutscene in every radio mission - I assume that would be too much work.

Are there other things that make the final boss satisfying to fight and defeat?

I think one good way to make a boss fight more satisfying to to draw it out and make it into something more than just a simple beat-down of an enemy. A good example of this would be the fight with Marshal Blitz in Who Will Die #3. Instead of just one quick battle, there are stages. First you have to take down the thingamajigs that make him invulnerable. Then you fight him directly for a while. Then he gets in an aircraft and you have to shoot it down. Then he gets out and you beat on him some more until he falls.

I know some players hate this kind of set up ("how many times do I have to kill this same guy?") but it avoids the situation where a boss fight is over surprisingly quick. I think Marshal Blitz was a tough fight, but even had he been easy, the battle would have been pretty memorable because there was a lot to it.

I think they tried to do the same thing with Wade at the end of #7 but for me it didn't really work because you're really just fighting his minions until he comes down and faces you himself--at which point I took him down way faster than I expected to.

Gimmicks.

Frostfire may not have a memorable appearance but the map he appears on is very memorable. I would also point out that he also has a cutscene. I just replayed Flux's arc, not having played it in quite some time, and apart from the addition of the cutscene it's pretty much exactly how I remember it the first time I played it 6+ years ago. Back then, Frostfire was pretty tough, and the first real challenge your character would face (the first Elite Boss too, I think). Of course, now my Street Justice Stalker was able to take him down in a few seconds.

As for Rommy, well, if you play the mission as intended you should easily defeat 300 soldiers by the time you reach him, it's just that skipping to the end then clearing is the common strategy.

Gimmicks are a good way of making a fight memorable, but as Coyote_Seven alluded to, it has to be a good gimmick. A bag of hitpoints is not an interesting gimmick. A boss fight with different stages, or a boss with a unique power, is memorable. In one of the Dark Astoria arcs there's a boss that actually gets level shifts the lower his HP gets, complete with a level-up animation. That was pretty memorable.