Which boss did you have the most difficulty defeating?

[The Entity]

The title question applies to both Chrono Trigger and Chrono Cross.

I found many of CC's bosses fairly challenging, but I was completely thrown off by Miguel. After first meeting the (very weak-looking) guy, I had no idea he would be a boss, let alone a difficult one, yet he defied all my expections and took out my team like it was nothing. He gave me quite a hard time my first playthrough, and it took a few tries to finally defeat him.

Which boss gave you the most trouble?

Oh, and this includes optional bosses, too.

[V_Translanka]

Those goddamn piranhas...Oh, wait, no RD love? Not actually a 'boss'? Whatever...

Anyways...Ocean Palace Lavos, Golem, Golem Twins & sorta Golem Boss (I didn't know he would run!)...And Zeal with her fuckass Hallation move...Pink Nu Spekkio for obvious reasons (if you don't have Frog or Robo to heal your whole party, you're kind of screwed [I refuse to use items on a boss that heals you completely even if you lose])...

Nu Master from CTDS is certainly one of the series hardest opponents right up there with Lavos & Pink Nu Spekkio...Oh and those two new demon bosses that regenerate if you don't kill them both at the same time put a strain on me as well because at first I thought one was a reviver like the Lavos Core, so I focused on the other one and then BLAMMO, it came right back...and my team wasn't set up real well elementally at the time to properly deal with them both so I just had to figure out in my head how much HP & damage I was dealing to kill them both off close enough in time not to screw myself...The fight was probably the longest I've fought in the series, I think...V_V

No one in CC really...Miguel was a close call though, certainly...Had to dig deep to keep my party alive in that one (all the way in Sprigg's Dodo form grid for that extra Revive Element), but that might be because I brought Harle along for the ride (but MoonShine helps goddamn it, I swear!)...

[placidchap]

CT - MasaMune
CC - Dario.

[Romana]

Golem Sisters in CTDS, eugh... In the SNES version I made use of emulator speed-up controls and overlevelled. In DS though, I was underlevelled and had to waste a few Elixirs on that fight. MasaMune gave me some trouble in my first SNES and DS playthroughs.

CC - HiHo Tank, Miguel, one of the Fort Dragonia bosses, Miguel, Dario... Garai too, I think.

[Shadow D. Darkman]

CT - Nizbel 1 (IDK why I had such a hard time in my last run through CT, and I was playing regular New Game for that run as I'd lost all my NewGame+ saves, but it is why I asked for ideal leveling areas for each chapter.)

CC - Hi-Ho Tank (Never could defeat it, and then I stopped playing. Didn't quit, just wasn't able to play the game.)

If I recall, the runner-up for CT was the Golem Twins Sisters. Holy crap, were they annoying.

[Lilka]

CT - Probably Zombor or Lavos form II, they're the only ones which gave me much trouble at all.
CC - Without a doubt, Criosphinx the hard way on a non NG+.  Honorable mention to Miguel, he hits like a truck and gave me a couple of losses my first time through, but once you know his moves, it gets a bit easier.

[Dunsparce]

Chrono Trigger: Golem Twins/Sisters
Chrono Cross: Miguel
Chrono Trigger DS: Nu Guardian (Master was easier to me)

[mav]

I guess it's been too long since I played CT--I can't remember having difficulty with anyone in particular...maybe the Golem Twins, but fuck I remember.

Now CC...that game had a couple bitches: HiHo Tank, Miguel, Dario, Garai.

Miguel stands out as one of the hardest during every play through, regardless of how amazing I thought I was. And Dario was ridiculous--didn't you have to have Riddel with you? That pissed me off. I didn't know the tricks to defeat him either, so I just tried to defeat him without any particular plan.

[Dark Serge]

CT: Golem and Ocean Palace Lavos
CC: Serge, Kid & my other teammate. Was impossible to defeat.

Ofcourse normal NG, not NG+. In NG+ everything is easy.

Btw, Dario was piss easy at all. He is programmed to counter every element kind with an element of his own. Using white and black elements results in him using powerful attacks, but all the others are status trash. Respectively: Red = Numble, Blue = Weaken, Yellow = BatEye and Green = LoRes. Numble and LoRes are most harmless, so if you just equip a shitload of red and green elements you can't lose. You'll only have to deal with some physical attacks.

[placidchap]

Btw, Dario was piss easy at all. He is programmed to counter every element kind with an element of his own. Using white and black elements results in him using powerful attacks, but all the others are status trash. Respectively: Red = Numble, Blue = Weaken, Yellow = BatEye and Green = LoRes. Numble and LoRes are most harmless, so if you just equip a shitload of red and green elements you can't lose. You'll only have to deal with some physical attacks.

Not exactly a known tidbit when playing for the first time, especially since back then I didn't use FAQs or walkthroughs...

[Dark Serge]

I didn't either, but I thought it was rather easy to figure out.

[dan0211]

It was the Golem Sisters for me until I remembered that the water counter attack was the weakest. Dream Devourer was difficult the first time, but now it's a piece of cake. Crimson Shade was difficult because my Lucca had been dangerously behind on tech learning.

[Shadow D. Darkman]

CT: Golem and Ocean Palace Lavos
CC: Serge, Kid & my other teammate. Was impossible to defeat.

Assuming that by "Golem" you mean the Golem that Dalton summons in Zeal Palace, I say this.

Zeal Palace Golem and Serge+Kid+??? were bosses you didn't have to beat to continue. You didn't have to lose, but winning had equal value in those fights.

As for O.P. Lavos, you actually had to lose to continue, whereas in the other two it didn't matter. If you defeated O.P. Lavos, it would continue until you either defeated Lavos Core or got pwned. If you won, you got the Developer's Ending. If you got pwned, you got the Day Of Lavos Ending.

I actually managed to get the Developer's Ending at the Ocean Palace. Personally I wonder what would've happened after the O.P. if you actually had managed to bring down Lavos instead of getting pwned like you were supposed to.

EDIT: I won't accept what I already said as an answer to that wondering, BTW. I had meant in the story.

[Dark Serge]

CT: Golem and Ocean Palace Lavos
CC: Serge, Kid & my other teammate. Was impossible to defeat.

Assuming that by "Golem" you mean the Golem that Dalton summons in Zeal Palace, I say this.

Zeal Palace Golem and Serge+Kid+??? were bosses you didn't have to beat to continue. You didn't have to lose, but winning had equal value in those fights.

As for O.P. Lavos, you actually had to lose to continue, whereas in the other two it didn't matter. If you defeated O.P. Lavos, it would continue until you either defeated Lavos Core or got pwned. If you won, you got the Developer's Ending. If you got pwned, you got the Day Of Lavos Ending.

I actually managed to get the Developer's Ending at the Ocean Palace. Personally I wonder what would've happened after the O.P. if you actually had managed to bring down Lavos instead of getting pwned like you were supposed to.

Yeah well they're still boss fights and if you win the scene changes, so you get that extra level of coolness. However I like the scene in Fort Dragonia more if you lose, 'cause if you win the third party member will be down for the count and he won't open his mouth again.

[Delta Dragon]

CT: I honestly don't know.  I didn't like the rust Tyrano.  I beat her without much trouble but the last time you fight Zeal was a pain. 
Same with Lavos's final form. 
CC: Miguel and Garai.  And probably Dario.