Dheginsea was one of the easist boss fights in the game for me. I blessed Purge, Blizzard, and Meteor tomes for my mages and slaughtered him from afar bringing in Ike and Tibarn for the finishing blow. That entire map was long string of ownage for my mages as they were slaughtering several dragons a turn from 10 squares away.

Eternal sonata.

part way through the game polka (my healer) got infected with eternal darkness (meaning she couldn't heal anymore). trash mobs weren't much of a problem so i kept on going, but then i got to the boss fight and it was impossible to win without a healer.

turns out (according to gamefaqs) that i was suppose to pick up an item in the previous level to cure polka. well it was too late to go back. I ended up having to grind 4 levels to so that fredrick would have a proper healing spell. the grind took about 2 hours. about 1 hour into the grind i saw an "x" on the ground and decided to pick it up, it was an optional boss fight that i of course lost, died, and lost my first hour of mob grinding. I was soo pissed i threw the game down for 2 weeks.

if it was WoW i would have thought nothing about the grind but in a consol game it just pissed me off soo much.

@Words of Wisdom 

If thats the case I am pretty much screwed. I guess I can start the chapter over and reconfigure my party. I knew I should have brought Tibarn instead of Naesala but I don't like breaking up my supports when I compose a team. I am going to have to figure out a way to defeat him without your strategy or I am going to have to restart the whole chapter...I really don't want to have to restart the whole chapter if I can help it.

stage 6-2 in Ninja Gaiden.

1. Every random encounter ever made in a game that has random encounters.
2. Every escort mission ever made in a game that has escort missions.
3. The end boss of Code:Veronica. I cannot describe how loudly I screamed "BULLSHIT!" when I realized that I had given every good weapon to the male character, saved over the game, and then walked into the final boss fight with the female character... It was impossible to win and Capcom gave the player no option to retrieve the good weapons from the other character. Terrible design choice and I never beat the game because of that.
4. Every Medusa head level in any Castlevania game.

 My sister feels your pain. I hate incredibly unobtrusive things presented as obstacles. In Rainbow Six: Vegas I remember I was in a theater and was going to enter from one side but the door was blocked, by an empty wooden shelf.

“Well men, the terrorists have won, they discovered we’re powerless over moving shelving.”

F.E.A.R. was awful about that. Seems like the developers constantly would block off doors with minor random junk blocking it from the other side. I’m a heavily armed super soldier, can’t I at least try and barge through the damn door. It’s just a shelf with some paint cans on it, I could probably knock it over.

The slow down during the boss fights in ODIN Sphere has to take the cake for gaming frustrations.

Escorting missions in Perfect Dark where like "ARGH". First, you had this useless dude, Jonathan, who used a pistol ALWAYS and shooted like one time per 5 seconds. Then you had Elvis, who with his gigantic head that was a magnet for headshots.

Also, many stars on Mario Galaxy get a honorable mention.

1. Hahah, nothing screams "immersive gameplay" like a "buzzzz-whoosh" noise while exploring so you can stop what you're doing and fight 5 pygmies holding spears.

2. Good point about RE4. That escort mission wasn't bad at all.

3. Whoops, whoever I was using didn't have any weapons. Meanwhile, by my best estimates, the other character was sitting having a smoke and coffee while armed more heavily than the 1st Marine Division. Good stuff.

4. Basically, anything that throws stuff at you in the non-MetroidVania games is "throw the controller" frustrating.

Goldeneye was the worst. That stupid bitch would literally walk in front of you when you were wide-open with an assault rifle.

When I beat that game on 007 mode, I probably killed her 25 times on accident.