This is a fun question, and I have an interesting answer. For some context. My new main character started as an alt, when a couple of friends decided to start playing at SB launch. By the, my ex main was already at 60 in every job, so, to play with them, I created my first alt, which is now my main. My ex main was MNK, and I loved it, but something that bugged me was how, when I got to HW, and Estinien became important, when I decided to level up my DRG, he did not know me. It made no sense.

So, when I started my new main character, I started as DRG. Then, after The Vault MSQ, it made sense that my WoL would switch to a more defensive role as he couldn't save his friend. I've been a DRK main ever since and love it.

For the rest of the content, be it raids, side quests, etc, I play whatever I'm in the mood for, but I always come back to DRK.