Dancer - Probably the easiest of the options. Some have compared the Dancer to an "Organic Lawnmower". I'd have to say the most mobile of the 3 jobs and exceptionally well suited for support. Everyone in my FC fights over my dancer partner buff when I play my Dancer and I'm almost always a welcome addition to any raid group for the increase in DPS a dancer brings. The down side, they are not top on DPS by a large margin although decent gear and good skills with the job as well as good RNG for your procs will change that fast I've found. And while not top dog on DPS, it is very fun to play with good range for single target and melee for most your AOE.

Ninja - I mained a ninja in ARR. Always fun and fast. They are also not always top dog on DPS but they still hold their own. You have the big con that most your abilities are melee range and positional meaning you have to be VERY good at dancing around your enemies and staying behind and flanking them. Also the only melee with some range attacks that can to decent damage, but you'll still be in melee range 90% of the time. The Mudra system is a little rough to get your head around at first but once your muscle memory has kicked in and you've memorized the combos it becomes easy. I'd say Ninja is fun but alot more work to master. Then there's the one ability EVERYONE loves from ninja.. Trick Attack. This is an attack that makes the mob take 5% MORE damage from ALL sources for 15 seconds and has only a 1 minute cooldown. So every minute everyone is doing 5% more damage if you keep this on cooldown and everyone loves it. I had a raid once with 3 ninjas and we had our trick attacks timed perfectly so the boss only had 10-15 seconds each minute that it wasn't debuffed. Fun class, more challenging though and great theme.

Summoner - Probably one of my biggest challenges right now. The basics of the job is DOT management. Keep your dots up on all or as many mobs as possible while managing all your cooldowns. It's a decently mobile class in combat, out of combat much slower. In my experience it's been rough getting my head around what I should be using and when.. but there is a clear cut theme.. keep dots up, pummel them with all your other attacks and summon you big hitters, Bahamut and Firebird, and watch yer cooldowns. In my opinion it's a higher skill floor meaning it takes more to understand and master it and a high skill ceiling. But once you have it sorted out they hit like a TRUCK. Keep in mind they are NOT fast, instant damage so in a dungeon they are not top dog on the trash, but on bosses and anything that lives more than a minute, they tear it up. They have a heal but it does not scale with their main stats so it's next to useless but they do have a resurrect spell which I use with my swift cast to make it instant and I can't tell you how many times I've save my party when a healer goes down by using a quick rez on them.