Your current playthrough's difficulty level

Used to play on normal, but switched to hardcore eventually, which is the sweet spot for me. I'm rarely interested in ultra-hard games because I just get frustrated and stop enjoying the game.

I was surprised by the difference it made in ME1. On normal, I largely ignored my squadmates and combat wasn't that enjoyable. Hardcore forced me to apply some team management and put squadmate powers to good use, and it also became more dynamic. ME1 combat started to make actual sense. It could have been great if the AI wasn't so terrible.

I'd give insanity a try but now I'm playing Andromeda. Maybe sometime in the future.

This is my second playthrough, and I'm on normal. I may try hardcore next time.

Depends for me if I just want to enjoy the story I will do normal. If I want to actually play the game and pay attention to combat and test myself I will play the hardest difficulties.

Currently doing an insanity play with a Vanguard. Rather fun testing myself. Seeing how much I can mess around before it bites me.

In ME2 I play on normal, ( Although on Haestrom I temporarily play on Hardcore ... so I can get the Geth Pulse Rifle. ) but in ME1 I start on casual and then around level 10/12 I set it to normal.

Insanity playthroughs are fun, but I really have to be in the mood for it.

I usually play Adept or Engineer, which tend to harder to play than the more gun-heavy classes. On ME1 and 2, enemies tended to have more armor and shields(Many powers such as singularity only work on unarmored, unshielded enemie). In ME3, the nerdier classes are less constrained with gun choices(Adepts can have assault rifles). In ME:A, Biotics and Engineers are much more powerful in comparison to the gun classes, because fewer enemies have shields and armor. As a matter of fact, I think soldiers are the hobbled class because ammo and batteries tend to be more finite(than in previous games), whereas powers are reusable.

I started playing the MET on Casual, since I thought I'd be done with it after playing one time and I just wanted to enjoy the story. But then I fell in love with the series and wanted all the trophies, and after my colleague encouraged me to go for Insanity, I did just that on my second run (well, Hardcore for ME1 since I had to unlock Insanity first).
I fell in love with the gameplay too along the way, so now it's always Insanity. Usually I'm not bothered by challenging myself since I play games for the story, but ME is a fun challenge and I enjoy trying to get better at it.

Buuuut sometimes I drop the difficulty to Narrative for Marauder Shields at the end of ME3, just because he's so frigging annoying

Oh yeah, sometimes I do this too. Marauder and his 3 sidekicks are very annoying.

I always play Casual on a first run to get a feel for the game and how the powers and weapons work. After that it's Normal. I honestly can't be arsed to bump it to Hardcore, much less Insanity. I'm just not that interested in the combat aspect of RPGs.

Seems like I'm one of the few that didn't have any trouble with that moment.

ME1 - Usually Insanity.
ME2 - Veteran, so I'm not stuck in cover all the time waiting for health to recharge every three seconds.
ME3 - Played it on Hardcore on my first and only playthrough. As a Vanguard, it was pretty easy.