I've played all the main Elder Scrolls games starting with Arena. Each game is always bitter sweet… though the margin is close, more sweet than bitter. Each game has some kind of hook to it that keeps me playing, while annoying the hell out of me non stop.
Arena came two years after Ultima Underworld. The gaming mags of the day had screen shots showcasing a 3D World and 3D dungeons similar to UW. So that was the initial hook. Arena was kind of a bland game but the dungeons kept me playing. Those were the days I loved being lost in dungeons.
Daggerfall was a bug ridden disaster but had a massive world and all kinds of great mechanics and character development. The UI constantly pissed me off but unlike many people, I really liked how complicated the dungeons were and how difficult they were. I also loved climbing structures and stealing. Was great fun.
Morrowind's hook was the spectacular graphics and Bethesda's noticeable improvement in execution of their game. The generic NPC dialog was the thorn in my side on that - just utterly a bore to talk with NPCs for the most part. Still, the factions, character development, and exploration were really fun.
Oblivion took graphics to yet a new level. Quests and overall simulation were wonderful in Oblivion. The UI and level scaling were the bitter part of that game. Of course these days, you can undo all of that with mods and it's great. Oblivion also had weird character progression that didn't feel like progression. Again, these days you can mod that right out. Out of all the main TES games, I replay Oblivion the most. I'm playing it right now in fact.
Skyrim like Morrowind and Oblivion was another big step up in visuals. I really loved a lot of the Skyrim gameplay but really disliked the main quest and fighting dragons all the time. I put over 1000 hours into Skyrim, but I have yet to replay it. I really hated the Skyrim UI but thankfully it did not take too long for SkyUI to come along.
Here's my short list of things that'd be nice for future TES games:
-Make a UI that is commensurate with the complexity of the game and make a separate UI for devices that use keyboard/mouse.
-Dungeons ought to be varied in look and feel as well as the kinds of creatures that occupy them. I'm a fan of fewer, but larger dungeons that have personality and are memorable. Dungeons are a world space and ought to have character. Why is that treasure chest there? Why do certain creatures occupy the dungeon. How is this world space serving the living things in the world. Skyrim and Oblivion dungeons were the ultimate "monster closets" - which is no compliment. I remember when I entered the Dungeon Destard in Ultima 7 for the first time back in the early 1990s. Today, after putting in 1000 hours in Skyrim and close to that in Oblivion no single dungeon really stands out as memorable. Perhaps Black Reach in Skyrim, but even that place was fairly uninteresting other than the hype built up about it in the game.
-This point isn't limited to TES games but is really a problem with most RPGs these days. A return to exciting gear finds is sorely lacking. Gear in games these days are piles of uninteresting junk. I miss the days where you find a ring and it truly benefits you. Or you find a better sword and it's really great. Gear in RPGs has become so drab and boring, players constantly throwing garbage on their ever growing pile of garbage. More is not better, more is actually boring. I want to be excited again when I find gear!