I started titan and have mainly stuck to the defender subclass until now. Striker is a lot of fun too. I've never done anything else (brief stint with Voidwalker) and never really had a desire to develop a Warlock of Hunter. I plan to Sunbreak as soon as I possibly can. Combine a Sunspot making titan with Dragon's Breath (functionally a Sun Spot making Rocket Launcher) and you have a badass recipe for a DoT powerhouse.