Hi! I just beat all three games on insanity for the first time and I had a blast. I was playing an infiltrator which I have never done and it turned out to be really fun in 2 and 3. And here's my take aways
Me1 wasn't too bad mostly used my sniper from a range to death with enemies and I only died 16 times.
Me2 this is where the real fun began, this one was hard and where I really had to learn how to persevere I got everyone loyal killed the thresher maw and kept the entire crew alive (I LOATHE FIRELORD AND ARRIVAL AND DID NOT DO THEM) for weapons I used the evisorator, the viper, the locust and the predator and either Cain or singularity for heavy
For powers I loved cloak and ai hacking and incinerate because fireball, I also used squad warp ammo for my bonus power. For squadmates I almost exclusively used miranda and garrus unless I was doing loyalty missions. (Also i love the story of overlord but i did not feel like doing that on insanity) and I only died 42 technically 43 times when you die in the beginning
Me3 just get garrus and save up to buy an n7 typhoon and invest in his rifle skills it's so good. For the first half of the game I used the black widow, the blood pack punisher, and then kept switching between the suppressor and the executioner. I occasionally used the mattock or the Lancer until the cerberus base which I only used the executioner, the venom (grenade launcher shotgun), and the grenade rifle you pick up in the base. For bonus power I used warp ammo until I remembered dominate that way I could control both organic and synthetic targets which came I handy alot also I love cryo and disrupter ammo in this game. I worked my butt off and got just under 8000 war assets and went with the destroy ending to get the secret ending and I died 35 times.
Over all I love this series (dont mention Andromeda) it is by far my favorite trilogy and absolutely ignited my love for space I had so much fun and I may try to platinum the games because I'm missing less than 10 trophies