I couldn't make a dual wielding warrior in Morrowind. In Skyrim, I can. In Morrowind, I couldn't make a character that forged his own weapons and armor. In Skyrim, I can (I think). And I know that in Oblivion, unless I went through the Mage's Guild questlines, I couldn't Enchant my own weapons and armor.
Oblivion took away my build. But I didn't cry about it. I adapted, and created a new build that fit that game. Coincidentally, I probably like my Oblivion character better than I like my Morrowind character.
Skyrim gives me build options that weren't possible in Oblivion, or even Morrowind. Yes, the guy who jumps high and runs fast isn't a viable build anymore, but I think we got a lot more diversity. And while people are on the negative side of the coin, with their builds being removed, perhaps I get to look at it through rose colored glasses because, except for the inability to summon more than 1 creature at a time (which Morrowind allows, Oblivion and Skyrim don't), Skyrim allows for the type of build that I always wanted, but was never able to have in Morrowind or Oblivion.
Merari, you're right, 21 > 18... but I believe those 18 skills allow us to do AT LEAST as much as the 21 skills in Oblivion, and I'd even go as far as to say they allow us to do more. The 18 skills may be less in number, but I believe them to be more in depth and complexity.
And even Morrowind's 27 skills... even those skill numbers are bloated by repetitive skills. 3 skills just for armor? Is Medium Armor *really* necessary? (Unarmored is, yes, and I believe it's a shame it was taken out). 2 skills for swords.
I dunno. People are freaking out about the lower number of skills, but I really don't think it's that big of an issue. Except for running and jumping, everything else is still there (okay, my condolences to spears...), and I think will be in greater depth than Oblivion or even Morrowind. At first I was concerned about the low number of skills as well, but now, not so much.