Most challenging and wanted DPS class?

[Allyrion]

I can only speak on the melee side.


Monk
MNK is (to me) the easiest melee by a good bit, once you get accustomed to constantly dancing around your positionals. It's focus after that (which is 99% muscle memory) is keeping GL stacks and maximizing downtime with meditate and form shift (to keep or regain GL faster). It's super fun and fast paced though.

- Good for raids. High personal dps with utility. May even outdps SAM at the end of this tier(340 ilvl) or the beginning of the next due to scaling.

Ninja
NIN is relatively forgiving when it comes to mechanics. It might be easier than MNK (to me) if not for the utility you can and should maximize. Also, while not as fast GCD-wise as MNK, it's a more hectic Job overall because of its many off-gcd abilities including, but not limited to, the Mudras.

- Almost mandatory spot for raids.


Samurai
SAM is a more demanding Job to optimize. It's base damage is very high, so you can do decently regardless but there's a big discrepancy between a good and bad SAM. It has a relatively involved resource management and priority system, but it's also really well designed and flows really well. It's like playing a Job with a manual transmission since you have a lot of control.

- Highest personal dps currently. No utility otherwise. Still quiet favored for raids due to popularity and high numbers.


Dragoon
I can't speak of DRG confidently. My friend who plays both SAM and DRG very well says that DRG is a little more challenging. I hold that opinion too but only in that DRG's rotation is involved AND mostly static. Almost the opposite of SAM since it has a relatively rigid long rotation. Despite that, it's still fun to play in practice and the Jumps are just super fun. It flows well once you memorize the priority.

- Lowest personal dps. High utility. Not in very high demand since many don't think it's buffs make up for it's low personal dps. They will probably be slightly buffed to NIN level since that's where their utility lies.


Difficulty, in general, is very subjective and really depends on your playstyle or just how your mind works. So take everything with a grain of salt.
Also the beauty of this game is that you can try them all. And if you use Palace of the Dead, you can see all their abilities up to 60, and play around with them, relatively early on to see which you like best. They all play pretty differently so I think it's best to try them for yourself.