Just a short list of Fighting Game Systems (Bells and Whistles) that worked.
Guilty Gear X2. Reload, & Accent Core (Guard System)
Probably one of my favorite guard systems ever invented. For one if you just blocked all day you opened yourself to major damage and even turning normal hits into counter hits. Also if a combo went on forever the damage scaling kicked in on the gauge reducing the damage to an absolute minimum. You also have bursting which if done at a perfect time filled your Overdrive guage to max. You had dead Angle Moves as well that may have done little damage but its a get out of face card.
CvS2 Grove System
This game offered choices on your style. So you didn't have to just settle for one method of play. You can pick the Groove that best suits your style. From Parrying to Charging your guage to a pissed off rage mode. So many choices than just one.
King of Fighters 11 (Judgement System)
A game where I've seen the game count not who has the greater life but who's performed the best in the fight. So if you ran out of time having more life doesn't neccessarily mean you win. Actions like blocking, countering, combo length, etc are what this system is looking for. There's even some infinite combos where the judgement system will count against you.
Dead or Alive Series (Counter System)
In some cases I don't like this system but its a rather fair system to play with. Landing counter hits really showed as in stagger hits leading to longer combos and more critical hits. But that's not where I'm focusing. With the proper timing and parry you could counter any incoming move being thrown at you. If you miss timed it you were punished for it.
Psychic Force 2012 (Life = Power System)
One of my favorite fighters of all time. Generally as a comeback method the more damage you take the more Psy power you have to use at your disposal. Making comebacks very possible.
Tatsunoko vs Capcom (Barouque system)
A personal favorite method of mine. A custom combo system at the sacrifice of some of your life. A good trade off instead of just instantly pulling infinites with ease.
Bloody Roar Primal Fury/Extreme (Beast System)
Build your meter to go into beast mode and have more moves opened up to you. Build it to max and you got a limited time of super beast mode. This wasn't bad at all with the guard system to dodge almost any moves (Although you did it by mashing guard). But getting hit hard enough and emptying the Beast Meter turned the character back to normal. As well as being able to transform mid-combo. Even more so as an added desperation move you can just go to super beast mode (forgot what its called and I don't have the book) at the cost of some of your life.
Those were some of the bells and whistles I liked about most fighting games.
Those were just a few bells and whistles I liked about games.