I use soldier, with a versatile selection of weapons for every situation. Anything, a soldier shep can't do a companion can back him up.
I use a shot gun for husks with either cryo ammo or incendiary ammo akes short work of them. I use snipers for mini bosses like mechs or scions. lol those guys are dangerous up close best to pick at em from a far from cover. lol If you can't beat a level pull out the heavy weapons. Mccain if you're nuts,but m77 does just fine. Haha if you run out of ammo use the pistol...I use the assault rifle for basic ground troops or synthetics like geth. With disruptor ammo it makes short work of any geth troops. Zaeed,Garrus, Mordin, samarah, Jack,grunt make great back up for various missions provding excellent support for Soldier shep. Garrus has overload, squad armor ammo, Zaeed has fire great for mobs and a sniper rifle for tough distant fights, mordin a mob devastator fire,cryo, Samara backs up powerful biotics with an assault rifle very versatile. Jack, haha she a good aim with the geth shotgun and her shockwave allows you to simple knock enemies off ledges making fights on plats forms really easy. They back up a soldier well. I also like to use immproved geth shields, I get a boost to weapons damage and I sustain less damage good for us run and gun types. if things get a little hairy use adrenaline helps take down heavies using m77 and mechs. I don't use concussive blast not worth the trade off for other skills. points are used better else where. plus, soldier is bad a...!