I realize the community divides into two parts on this subject: those who care about cosmetic appearance and those who don't. If you don't care, that's fine; this thread is intended for those of us who believe accessorizing matters in MMOs.
Here's my wish list:
1) A cosmetic armor tab such as they already have in games like Rift and LoTRO. In several cases, the tier one and two stuff looks much better than the sets that replace it.
2) Dyable weapons (I realize this is coming...some day). Until then, lose the shiny red metallic color I'm forced to use with my CH160 gear. It clashes.
3) Get rid of the hip flaps, I'm not a medieval Japanese Samurai. At least for the light and medium pieces.
4) Make a toggle to show/hide shoulders and gloves. Most of the light armor looks better without.
5) Costumes should be dyable with a single primary/secondary/tertiary color palette for the whole ensemble.
6) race-specific undergarments to replace that generic black placeholder thing.
7) Any bearded Nord who equips the wedding dress costume should take a 10% hit against health and stamina.
I may be kidding about number 7...
Walking Dead survival tip ... just run faster than Otis