Which ME do you think is the hardest 1st time around?

It's generally safe to assume that "difficulty" questions are based upon Insanity as the benchmark.

I think I struggled, initially, with MEA the most. It wasn't even the gameplay that frustrated me. I expect to die a few times while learning an entirely new game with a "Level Chump" player character. In combination with the save system, though, I got annoyed as hell and dropped to Nightmare, briefly (from around Levels 8-14). I regretted it, since I now have to wait an extra playthrough for my trophy; and I won't feel I've earned it until I achieve it with a fresh, Level 1 Pathfinder.

ME2 felt pretty challenging on my first Insanity playthrough, but I didn't get frustrated. ME2 and MEA are fun enough to keep things interesting. Neither of them is all that difficult, now, having learned to play.

ME1 was "grindy", since enemies soaked so much damage. I never played ME3 w/o an imported character. It's a cakewalk starting st Level 30, though. Insanity feels much like normal in ME3.

The MEA save feature is a fun-drainer, for sure, when trying to learn the game. If they fix the save feature, I'll be happier all around.