I've flip-flopped back and forth but I think I've landed on hunter (night elf). I played a dwarf hunter vanilla through wrath and then again in WoD and Legion, but never raided vanilla and only did about half of TBC. Like you said, I wanna "complete" the character I made, but more the class. Dwarves are great but look kinda shit in higher level hunter gear, female night elves look awesome so I'm going for that. Some great advantages to being a hunter and I've already raided top-end content with one. Aside from that, probably a warrior and priest alt too for tank/heal shenanigans.
Also, wisp form doesn't hurt as well.
Trying to decide between an UD lock or a gnome mage. LOL decisions, decisions.
My first character was actually a UD warrior, a dual-wielding warrior. Led me to abandon him after hitting lvl 26 or so and making a Troll Shaman instead. Most of my alliance characters were human females, mostly because their models looked really good in my opinion. That's kind of what happens when you have overly muscular male characters, which I felt didn't fit my human rogue or my human warlock.