Favorite builds

Tech Soldier :
Concussive Shot
Invasion
Turbocharge (or Assault Turret)

Adept :
Double Warp
Double Thrown
Backlash

Vanguard :
Charge
Nova
Concussive Shot (Warp would be better but I keep a combat power for RP purpose)

Engineer :
Energy Drain
Incinerate
Remnant VI (or Shield Boost for viability)

This is the area I felt the game was its weakest in gameplay. 3 active powers with access to all powers and a crappy way to change powers is just off. I usually just stuck with 3 powers for like 95% of the play through which then defeats the entire purpose of unlocking and maxing out all those powers.

I've tried a lot of builds but through multiplayer and my favorite there is the human adept so I my SP playthroughs are usually a similar build.

My current which I'm just starting
singularity
Pull
Throw
Sidewinder.

It's not like it was worth using more than 4 powers in ME2&3 anyway and you couldn't even get creative about it.

That's not what I meant. You have the exact same powers in every playthrough (on the same class) no matter what. You could only switch out 1 power.

Also if they'd allow you to use 8 powers in MEA you'd just pick the 8 most busted powers and blow everything up. And it would also decrease build diversity. For example the 4 builds I posted above are 1 power short of fitting into 8 slots (like in MET) so those 4 thematic, coherent builds would be just one overpowerd mess without idenity.

The more points you put into a category the better the passives are tho. So it's not entirely pointless.

I try to use different powers but I always settle on:
Adept: Nova, Charge and Annihilation Field, for mobs.
Soldier: Turbo Charge, Flak Canon and Omni Grenade(or Concussive Shot) for fiends, destroyers and architects
Backlash for Ascendents

I use the other two favs just for fun. A classic infiltrator with black widow, or perhaps some singularity, pulls and throws

Meh, enemies scaled with you so it was just basically staying even. It never went, oh look now my biotic explosion kills in one hit. And even if there were a substantive difference its just numbers or damage in a easy shooter.  So I have to shoot them one more or less time, I'm not too concerned. Deciding which power to use out of a larger array on the fly I find more compelling.

I liked the game, the gameplay overall was good.  But the 3 powers thing was weak IMO, other things were more just irritating like gun balance sucked and rarity on crafted items you almost automatically got the recipe for was kind of silly.  All it did was overly persuade you to only research ultra rare as it gave you more augments and they were generally better guns.  The pirahana was a standout i the only rare category. But overall, UR just better and even among shotguns for most builds the Dhan is better, but given its low clip size it doesn't work great with bioconvertor builds. Speaking of research, way too few research points it made you feel almost locked in to a small set of guns. On replays you can get a bigger picture, but I don;t think it should require it. But that's a minor bitch, the only one that I think really weakened the experience was the limit of 3 active powers.

My favorite build is still probably the basic infiltrator: Tactical Cloak, Incinerate, and Energy Drain, Black Widow SR. I regularly switch into a Biotic profile with various powers, but often keep the Tactical Cloak skill in order to get into close range undetected or as a fallback for getting myself out of trouble.

I enjoy switching profiles up. Since I generally make my changes during the lulls in combat that exist in all the missions have, the short cooldown that people seem to love to complain about is not a factor for me in the least. I also find that I am quite able to synchronize my use of my own powers to affect enemies my squad have primed for me since they generally tell me what it is they're doing with phrases like "Gravity goes away in 3, 2, 1" or "He's vulnerable, hit him now." It certainly beats the AI in ME1, where, if left to use their own powers at all, squad mates would blow their entire wad upon first entering into combat or in ME2 where after you used 1 power each from everybody, powers all went into cooldown (effectively limiting you to using 3 at a time anyways).

I also enjoy that any class can carry any combination of weapons and that the passives from all profile areas (combat, tech, and biotic) are always on (so my biotic profiles can still carry 4 weapons or 2 or 3 heavier ones without affecting the cooldowns.

I really liked that I could effectively sample all the powers during my first playthrough... I didn't have to start new games with a new PC in order to change from being an engineer to being an adept. I didn't have to start whole new playthroughs in order to get all the skill related achievements as well, something that was simply not possible to do in a single playthrough in ME1. I also enjoyed being able to change my Ryder's name and gender when importing into a new game plus. IMO, Bioware made the system far more flexible and far more enjoyable.

I’ve done some tinkering and playtesting and I’ve changed up my Vanguard and Explorer builds. I couldn’t get the Pathfinder shotgun to be useful. It’s the worse of the set. Now that I’ve rearranged powers, it’s far more effective being the kill shot after a tech combo detonated by charge. So now the builds are:

Scott 1 (Casual/Logical)-Explorer

(T) Overload (ABB)
(C) Omni Grenade (AAA)
( Charge (AAA)

Pathfinder Deep Impact shotgun
Asari Sword

Pathfinder Vigilant Helmet
Kett Unity Chest (Adrenaline Mod)
Pathfinder Vigilant Arms
Pathfinder Vigilant Legs

and

Sarah 2 (Emotional/Casual)-
Vanguard

(C) Turbocharge (BAB)
( Annihilation (AAB)
( Backlash (ABB)

Pathfinder Ranger pistol
Kett Carfalon

N7 Helmet
Pathfinder Vigilant Chest (Adrenaline Mod)
N7 Arms
N7 Legs

Turbocharge
Charge
Tactical Cloak or Energy Drain

Valkyrie with Auto Fire, Bio Converter and Kinetic Coils

Mix of Maverick and Kett armor

Everything on Insanity dies in seconds...

Never did a second playthrough.