I want to try a DPS class

[Arkenne]

I've played on the big pings and the one that responded the best to me was BLM.
Pretty much MNK too, didn't even notice I was on the 300+ until I changed to NIN later on...

[Mercurias]

Dragoon is one of those classes that most people have leveled at least somewhat due to how nice Blood for Blood is and how many jobs use it (BRD, MNK, MCH, and NIN). It's also a really solid 'starter' melee DPS class. On top of having high HP and defense for a DPS class, you'll learn positioning (though not as important as NIN or MNK), how to apply and time DoTs (though not as important as for BRD, SMN, or SCH), how to watch your buff/debuff timers, how to synergize lots of cooldowns for maximum DPS, and handle a complex rotation all in one job.

And that doesn't even go into how to handle your jumps for gap closing and gauging distances for tricky maneuvers with Elusive Jump.

A lot of folks like to make cracks about Dragoons tanking the floor, and to be fair, there are plenty of bad Dragoons out there, but it's actually a job with a whole heck of a lot of complexity and a skill cap I'd approximate at pretty close to NIN.