Morrowind had the problem that there were too many shiny "toys" lying around with nothing to prevent a Level 1 character from waltzing in and picking them up. It was NOT a good solution to remove those offending items from the game entirely until the character reached a certain level (as was done in OB). A better answer would be to place a fixed-level adversary in the area, so the character had to EARN the reward, and a low-level character would either need to do something pretty spectacular to get the reward or else come back a few levels later.
The problem with fixed-level adversaries is that they stop offering any serious challenge after a certain point (which was the problem in MW that led to OB's scaling system in response). Better solutions could be to either add additional levelled opponents (randomized, so they could either be at your level or lower) along with the fixed one, or to increase the difficulty of the first opponent at a reduced rate from that of your character, or only start increasing it after the character hits a certain point. Having your L1 character facing L10 opponents in someplace you really don't belong is fine with me, because you can go there at L15 and clean the floor with them; having every opponent in the place at L1 when you're starting, yet L15 when you're improved makes no sense, and is ONLY a viable mechanic in a pure "fight" game, NOT a RPG.
In short, MW's opponents were sometimes a little TOO fixed, or entirely missing where they were needed, while OB's were blatantly over-scaled. That "too fixed" situation is good in some places, such as in whatever the game uses for a "starting" or "civilized" area. As you venture further, or into more "forbidding" terrain, the odds of higher-level opponents appearing regardless of your level should increase. FO3 did NOT get that right, where high-level creatures would spawn right outside (and eventually INSIDE) the front gate at Megaton.
To avoid a surplus of "uber" items as the game progresses, the amount of "high end" items should be extremely limited, so their acquisition is something "special". Loot (and dungeon occupants as well) should not respawn like clockwork every three days, and if they respawn after some longer (and hopefully randomized) time, neither the loot nor the strongest opponents' gear should typically be as valuable as the first time around (except for the occasional random "extra-shiny" item now and then), rather than getting progressively better as the game went on (as in OB). That should provide incentive to explore new areas, not an excuse to keep going back and "milking" the same spot over and over every three days. Common bandits should NEVER end up walking around in Glass or Daedric armor, otherwise they wouldn't be "common bandits" anymore, they'd be rich and retired from banditry. Of course, it would be nice if all the pieces for those high-end armor sets are actually THERE in the basic game (unlike in MW, where one of the Daedric pieces was only available by killing a critical NPC. OOPS, small oversight.).
Most importantly, later spawns should never REPLACE the basic ones, only supplement them. If I stop encountering Wolves, for example, and now there are only Dire Wolves, there'd better be some rational in-game reason behind it as part of the plotline. Also, if there are more spawn points, but lower chances of anything spawning at each one, that removes the "certainty" that you know everything that's around you. When you see one creature hanging around the "usual spot", that should still be no guarantee that you won't encounter something else from another nearby "less likely" spawnpoint that you just weren't aware of. After a while, in MW, you could tell at a glance what was there, and most places ceased to be "threatening". That SHOULD be the case in the "safer" areas, but was a bad thing out in the wilderness.
This!!!
I agree, and I'd like to take it a bit further. When enemies spawn in a certain area, they should always spawn in that area. Why would certain creatures go extinct because I gained a few levels? Not only that, but leveling these creatures (to a great extent) doesn't make a whole lot of sense either, as wild animals don't really exactly practice their fighting skills and simply do what they need to survive. You also wouldn't expect bandits and basic human enemies to level very fast, as they do not train near as much as the character in combat. Some leveling would be appropriate but again, the player should whip them at higher levels. The enemies that should scale are those where it makes sense: cultists who have built their lives around protecting some ancient relic, warriors and mages also searching for the same artifact as you (and are willing to kill you to get rid of the competition), and enemies tasked with protecting their own encampments and cities (should you become hostile with them, you have a challenging fight ahead of you).
Equipment for enemies should also make sense. As Kovacius said, bandits and thieves shouldn't be wielding full daedric gear and glass weapons. I mean, did they rob a daedra? I kind of felt like human enemies had some common weapon and armor smith who started out retarded in the beginning of the game, but by the time you reached level 20, he was stephen hawking. Powerful armor and weapons should be in the hands of powerful people, otherwise they are just common. And the most powerful artifacts should either be guarded by some cult or formidable group in the game (who either worship the artifact or want to make sure the artifact never comes into anyone's possession again), or there should be another adventurer searching for the same artifact, and be ready to fight anyone who found it first to take it. Having the best armor and weapons in the game easily attainable by anyone at any level is just stupid, and defeats the idea of skill being a requirement to obtain certain things in the game.
One of my first posts on this topic said that in areas should be leveled, with enemies of level x to y spawning there, thereby forcing players to explore and quest in each leveled area and experiencing the entire game. This would also allow for "best armor and weapons in the game" since the PC would have to be high enough level to even attempt to get them. Then, certain dungeons and areas in the game should be scaled, so that players who play through and would like to continue leveling their character could do so, and these dungeons could have random drops which, at certain levels, are better than anything you could get in the regular game world, although these drops would have to be exceedingly rare. I would like to see a bit more fixed stats in terms of weapons and armor, so that the same armor that I have isn't better for some reason on some other enemy at higher level. I would also like there to be certain enemies in the game that are storied, such as dragons and famous warriors, who live in certain places or wander the world and are very high level and drop some of the best gear in the game, providing some more high end content and further challenge for people who have completed the MQ or are very close to doing so.