Engineer is the biggest "must-have" in the game. I wouldn't call it a crutch. I would call bouncing betties and claymores the crutches, and Engineer is the baseball bat that knocks the crutches out from under the enemy.
Primary Gunfighter Spent a permanent unlock on it because I want QD, stock, acog on everything. Also seconding Ghost in HC, nobody uses it so when an enemy calls in a UAV I catch them completely off guard.
Watch me battle Pokemanz: http://www.youtube.com/user/TheBoj0
for my playstyle i have to use ghost on almost every class. Since I flank for most of the game. Nothing will be happening and then as soon as I am alone and right behind the enemy team...... enemy uav inbound.
Another would be claymore on almost every class... idk what the obsession with betties is in this game becuase they are so easy to dodge even without engineer. With a claymore unless they have engineer you will get a kill almost every time.
I suppose my only crutch would be hardline. I play just fine without it but I enjoy being able to chain my killstreaks that much easier. Other than that, there's nothing in the game that I consider putting on every class. I do them all separately.
Toughness is for pansies.
Soul Silver FC - 4469 3620 2054 / Diamond FC - 1033 3883 0634