QUOTE
What do you mean bending the rules a bit?
Well, in Morrowind, it used to be that any master trainer would train you past 100 in a given skill, provided that your level in its governing attribute is greater than 100. Skillbooks would also train you past 100, regardless of your attributes. Of course, neither of these actually increased the skill in question -- they just pushed the "skill increases before level-up" marker down by a notch.
On the other side of things, you could decrease your skills specifically to train them back up again and get the normal decrease to the number of skill increases needed before level-up. Stealing an object worth, say, 4940 gold was effective in doing this, since you'd rot in prison so long that most of your skills would decrease as a result of disuse.
Magic was also an option -- spells that damage or drain skills always had predictable effects. I guess the most effective method of achieving unnaturally high levels would have been to have a junk skill like Spear as one of your minors and enchanting something with CE damage skill at 1 point on self. That way, your spear skill would always be at 0, so training would have be pretty much free, and any person off the street could've trained you. 500 continuous training sessions later, you would've gained 50 levels right there on the spot; since with every level-up, you would've been getting x5 in Endurance, with the proper precautions, you would have
always gotten the maximum health increase, too.
I'm sure that people will find similar sorts of things going on with Oblivion in time -- the training limit per level makes them harder, though.