*LONG* I've read a lot of comments on this thread and thunk on it hard. [b]Halo CE:[/b] In Halo CE [i]The Library[/i] eventually became a challenge and good practice, and I had little trouble with the level [i]Keyes[/i] once I figured out I had to rush to keep the captain alive. Everything felt fair in that game. Most frustrating in CE for me would probably be [i]343 Guilty Spark[/i] just because it felt super exciting the first time and then quite tedious after the third play through.. [b]Halo 2:[/b] It seems to me that I got less frustrated by dying in Halo 2 than Halo 3 because it didn't impact overall stats in any way. But the snipers as many pointed out here were awfully quick at aiming and one shotting you on many occasions in Halo 2. They won't bug you a whole level, but some at some points I had jackal placements memorized to perfection. Good thing they weren't more random. The structure were you encounter a gauss hog in[i] Metropolis[/i], the waterfall area in [i]Delta Halo[/i] and sniper alley in [i]Outskirts[/i] in particular. Most frustrating still, would probably be [i]Quarantine Zone[/i]. I just didn't care for it. Had a blast otherwise. [b]Halo 3:[/b] This game I found was play tested very well. They avoided the earlier weird annoyances. Most frustrating thing in this game were the Buggers, I think. You get fed up with them sometimes.[i] Cortana[/i] takes the cake, though, because of the unskippable cinematic control yank making you have to turtle your way forward. [b]ODST: [/b] For me the most frustrating was the last level. The garbage truck explode so easily, and the very last firefight in this level felt too much like... Firefight. [b]Reach:[/b] I do not like the AA MAC gun thing on PoA. Otherwise I had a blast. [b]Halo 4:[/b] Loosing weapons in sniper valley. I try to juggle three weapons here on Legendary. They despawn sooo quickly. Argh. Only played Halo Wars a little so I can't say.