Some good answers already, but here is my take on it. They are the most versatile class, can be built either for pure aggression or pure defense. They are never not useful, in whatever you're playing. Punching. Purple boobs. Flashbang grenades to blind enemies. Have the highest vertical jump, or horizontal thrust that rivals blink in movement speed over long distance if you stagger boost your jetpack. Most of the titan armour looks really good. Most of the titan exotics are extremely useful, and all of them have their situational use. Probably the strongest keystone class around which to build a solid fire team for raids or whatever. Complements both hunters and warlocks really well. PUNCHING!