I have three DMs that grant our characters significant power-ups. They all have us be PCs "...of destiny"
The first one lets us increase a stat point every level (although not the same one twice in a row,) and on the 4th, 8th, 12th, we get a special ability instead. At 4th we had the ability to roll against a new skill to grant ourself a die reroll once a day. The DC is based on the time we take to activate it. 15 for standard action, 20 for move action, 25 for swift, and 30 for immediate. At 8th, we have the ability to "go home early" and yank our character out of reality for the rest of the game session (which makes perfect sense in campaign; I know that's wierd.) At 12th, we are immune to divination (as Mind Blank,) and boy are we happy to get that as divinations are used heavily against us. We are Anakah--the fateless; thus we threaten the gods themselves.
The second DM has every four levels get a bonus feat, a +1 bonus to one save, a +2 to bonus to a save, then the regular stat increase that already exists in the rules. Plus we have all been going around colleting minor artefacts that grants us kewl powerz.
The third DM is a power gamer, and he loves having his players wield power. It's an Eberron game and we are all "incarnates." Of course, we are questing to find out what that's all about but at first level we got to add a bonus 1d6 to our hit points, after that...
-Incarnate Abilities-
-Odd Levels – (Number of times can be taken)
1+ :+1 Stat Point inherent ( 5 )
2+ :+2 Action Points ( 1 )
4+ : Energy Missile - 1d4, R-short, ( 3 )
(add bonus energy damage of your choice to your ranged attacks, or shoot it by itself as a ranged touch attack within short range)
1+ :+10 skill points ( 2 )
4+ :Energy Melee - 1d4 ( 3 )
(add bonus energy damage to all of your melee attacks)
- Even Levels – (Number of times can be taken)
3+ : +1 insight to a save ( 5 )
3+ : +1 insight armor class ( 5 )
5+ : +1 enhancement to Base Attack ( 3 )
4+ : +1 feat ( 3 )
5+ : +1 caster levels, <all caster levels> ( 1 )
The number in front is the CHA + CON modifiers that is required to be able to select that ability. Lucklily, I'm playing a Warlock.

I have taken the +10 ranks of skill points twice already and the bonus feats.
But...that's not all! We also all have items of legacy! Mine's a spiked gauntlet that looks like a scorpion stinger that was slammed onto my hand from a "dead" balor while he exclaimed "I will not be denied!" after we pulled a sword of legacy out of his "corpse". Right now it's a +1 item that does a triple strength Mage Hand 3/day. And I can't remove it, of course. Turns out that it used to belong to my paladin dad whom I don't know much about.
Well, I'm definately getting my "power gamer" emotional kick sated.
Me? I don't have any power ups for the players of my one shot adventure--except that players create a 21st level character with 1,000,000 gp of items.
