How much of a raise should a CEO get in a year? Which would seem reasonable? 10% or 510% ?

in 2010

TRW CEO John Plant got 510% raise over his 2009 salary of 6.7 million
Ford CEO Alan Mulally 524% raise... yet his company has 14 billion in debt
Johnson Controls' Stephen Roell 424% raise

So... did those 3 companies make 4 to 500% better business decisions? Better profit? Better products?

Doubt it.

I read about this in the article by Jamie Kitman in Automobile Magazine, his source, and the full story is at http://www.autonews.com/apps/pbcs.dll/article?AID=/20110613/OEM02/306139854&sectioncat=product&template=printart

Plant's base salary was $1.9 million, but he made $28 million from stock option gains. Bonuses, stock awards and other means of compensation accounted for the rest of Plant's pay.
The $9.45 million bonus package Mulally received in 2010 was almost three times as much as his total compensation from 2009. The Ford CEO also earned $9.3 million in stock award gains and $1.4 million in base salary.

The median salary of CEOs who held their job for at least two years rose from $3 million in 2009 to $5.7 million in 2010, an increase of more than 90 percent from 2009, Equilar research analyst Aaron Boyd said.