Favorite Class(es)

Engineer is easily my favorite, and the class of choice for my canon Shepard. Sentinel isn't too far behind for second place.

I have to make a revision. I replayed the series as an Infiltrator in ME2. In ME2 I concentrated more on power recharge time than weapon damage and it was more fun. I felt more like an engineer who was good with guns. I took energy drain as a bonus power so it was even more fun. And in ME3 there are so many ways to play this class. It has gone up considerably because of this. However, Vanguard is still one of my least favorite.

The Vanguard class has "a special place in my heart" because it was my first class in Mass Effect.
Before I knew what was going on, and before I understood all the abilities and mechanics and the "roles" that each class is designed for, I went for the ultra-sophisticated method of "What looks the coolest?"

The Sentinel class caught my eye (I love that word: SENTINEL; you never find a villain who's a Sentinel, it's always a hero who's a "Sentinel"), point being that while it had my attention, something compelled me to pick the Vanguard.
It was likely seeing how Biotic Charge makes one invulnerable while doing so, and this was also at a time where my burgeoning interest in role-playing led me to consider that I like "magic knight" classes, i.e. in the holy trinity of magic, might, and mischief I prefer a mix of magic and might.

I knew that biotics were "magic" and that guns were "might" so the class that blends both looked like the best fit.

Boy howdy was I correct!

[Loads of fun, laughs, tears, and replays later...]

After fine-tuning what I like in 'my' character class overall, I realized that I didn't just like "magic knights" but "combat medics" most specifically.
They're always good in a team, have healing abilites, and in most modern scenarios, they carry shotguns.
I love shotguns.

Doing a trilogy run, I saw how the Sentinel class in ME1 used defensive biotics and healing tech, and so while I love Vanguard, I find my 'mindset' is really more of a Sentinel.
Not to be terribly philosophical, but my 'thinking' is more in line with the Sentinel class than the Vanguard class.
Specifically to Mass Effect, I find that I prefer biotic-hybrids over JUST biotics.
If Vanguard is supposed to be aggressive and Sentinel is supposed to be tactical.....
Well, I play my Vanguard tactical and my Sentinel aggressive.

Since I play on PC, I sometimes will mod my save to change my class, with head-canon as my Shepard being a Vanguard/Sentinel hybrid class, switching between the two as the mission required.
The tricky bit was having to go to Deck 3 to switch my bonus power, sometimes I would go in Sentinel and realize that I forgot my Warp Ammo...
"Ah, my guns, they're so WEAK!"
Or I go in Vanguard and I forgot my Flare...
"Ah, my powers, my gun is purple..."
Dangit.

This is why I made the poll with two votes, because I really can't pick just one.
If I absolutely had to pick based on heart, I would pick Vanguard, because it was my first instinct. Power-&-Light, Fire-&-Ice.
If I absolutely had to pick based on mind, I would pick Sentinel, because it is versatility defined. No Fear, Armored and Ready.

I also find that those are the classes that have the most 'uniqueness' in the whole trilogy, Plenty of Adepts, Engineers, and Soldiers for squadmates, and Garrus.
But there's only two dedicated Vanguards in the whole trilogy you meet; one of them is a mini-boss and the other is only in your squad for the second game.
There are only three Sentinel squadmates in the whole trilogy, one who can die in the first or third game, one who always dies in the third game, and one in the second game who any doing an Insanity run will swear by because of her sheer usefulness but can die in either the second or third game.
Playing as an Adept, Engineer, or Soldier just feels redundant because no matter what, you're going to have a nearly-identical skill-set to a squadmate.
Infiltrator is a bit strange because if you need a combat/tech hybrid, use Garrus.  Because Garrus.

Don't get me wrong, I'm not knocking those other four classes; having tried them all they are powerful in their own right.  But as a Vanguard/Sentinel I really feel like I'm bringing something special to the intergalactic table.
I pick Vanguard and Sentinel because I get to be a Superhero and/or a Shining Knight, two of my favorite characters to play as.

Yeah, that's the plan. On rank 6 I'm going to use a bonus power instead of weapon damage. So I can use energy drain and still remain cloaked which would be awesome. Its just that infiltrator has several ways to play it and it can use a wide variety of weapons and still be extremely effective.

I have no issue with Vanguards as a class. I just hate how buggy this damn class is for me. In ME2, I've had many instances where charge doesn't activate, charges goes nowhere (it looks like Shepard trips) but I still have to cool down, and other glitches. I play on Insanity in ME2 and Vanguard was the least fun on insanity because of these issues I've had. I like that its more tactical in ME2. Even on multiplayer, I'll be doing really well with the Slayer only for charge to not activate on a Phantom and it will ruin my flow completely. Its kind of annoying.

In ME3 its just brain dead overpowered its silly. Its those reasons why its my least favorite. When it works right, its pretty fun. But too many deaths from the glitchy class has made me hate it. 

I've beaten insanity with every class. Vanguard was the worst class because you can't really be aggressive in general. You are smart not to play it on insanity. The glitches makes it more annoying. Surprisingly, I found Kasumi to be the one who saved my Vanguard insanity run and made it more fun. Kasumi/Thane was the team for that run. Which actually made me like Kasumi more than I already do. But yeah Sentinel is awesome on insanity, so is Engineer. Soldier and Infiltrator are easy as well. Adept is the most challenging but satisfying. But Engineer and Sentinel are the most fun.

Sentinel because I like to be a jack-of-all-trades. Also, tech armor.
Engineer because pets make everything more fun. Also, space elemental wizard. (As opposed to the Adept, who I think of more as a telekinetic.)

Vanguard did make me cackle with glee, though.

The Vanguard.

Vanguard and Sentinel

Vanguard because...hell, Charge+Nova combo is one of my favorite things to do in ME3, charge in...smash your hand to the ground and BOOM!
and I'm becoming to really like the Sentinel because its sort of a Jack-of-all-Trades class, and it's just fun

I'm just partial toward the biotic classes, I love how biotics are portrayed and it's sort of like magic...only science based
I've yet to try out the pure Adept class, but I might do that in the future (or maybe when I get around to playing Andromeda )

That's basically me, right there.

Sentinel and Engineer. I was going to pick Adept instead of Sentinel but then I remembered them getting consistently nerfed through the series, to the point where in ME3 if you want to play a Biotic power class you're better off as a Vanguard or Sentinel. I still prefer the concept of the Adept, just not the execution.

I was also going to pick Infiltrator instead of Engineer but I only really like Tactical Cloak, not really enough to pick it. I do think Tech powers were better than Biotics after the addition of the protection system but I love the concept of Biotics so much, so Sentinel is a great blend. That said, I do detest how the game, specifically ME3 (even more so the Citadel DLC) treats the Sentinel as a primarily Tech based class. I wanted my Shepard to use Biotics to fight off his clone like the Adept and Vanguard does :'(

Vanguard though I have also rolled quite a few soldiers.