So far I've really enjoyed the Elder Scrolls series starting with "Morrowind". The only thing I would really like to see is maybe some improved/added mechanics. One thing I've always wanted to see in open world RPGs is vertical movement.
When I was a kid and played D&D with my friends I always liked the Thief class because of his wall climbing ability. I've always wanted to see something like that implemented in cRPGs. I would also like to see the crafting toned down. I would say the crafting mechanics in "Skyrim" was the one thing I really hated about it and I hold it up as an example of how crafting in games has gotten out of control. Crafting in Skyrim is the reason I have over 150 hours on a character instead of 90. Crafting in Skyrim is the reason I feel compelled to check every single container in every single room and pickup every item that isn't nailed down. Crating is the reason I'm constantly managing my inventory and fast-travelling back to my home base every hour to dump crafting mats. Yeah, I know it's optional but it's one of those habits that's really hard to break.
Actually Daggerfall had that; you could go total Spiderman on the town walls. And it was a selling point of assassins/acrobats.
My own wishes:
Deleveled rewards and challenges. It sucks knowing that if I put the quest off until level 30 I could have gotten much better rewards. At the same time I might venture somewhere at level 1 and never level to keep a parity of levels with my enemies whilst improving my gear. I
might be level 1, but I'll be twinked out in the most godly gear you've ever seen a level 1 wear.
Re: Magic
After Morrowind things went downhill on the magic end. No levitation, spellcrafting was downscaled and eventually deleted. By Skyrim it's pathetic, a gutted shadow of its former self.
The powertrip fantasy of being a mighty mage who had a rough start but earned unlimited power? Well kinda there if you count enchanting to 0 cost spells or chugging down more magicka bottles than a frat's yearly consumption. But it scales linearly (read poorly) compared to warrior's quadratic weapon/armor perks^enchanting^smithing.
I'd like a stock magic experience that doesn't handhold the initial levels but becomes truly powerful ie like Requiem does. 0 skill? Pitiful damage. 25? Somewhat weak single target. 50? First AoE and good damage. 75? Walking artillery. Like you can imagine Imperial battlemages being terrifying. 100? Bend reality, punt someone miles into the air, conjure tactical nukes with a flick of the wrist. Competent to become a Lich, an Archmage or just casually live 5000 years like Dyvath Fyr.
Oh and to become the Archmage, you should be legitimately powerful and skilled in the arcane. You should have to demonstrate said skills in a suitable challenges requiring said arcane means. Ie not accessible to a 2-syllable Orc with explosive farts.