Liam Gallagher is a complete jerk, egotistical and untalented. Noel, however is a true artist and from what I've heard, a very down to Earth guy. He used to guest on Russell Brand's BBC radio show, and he sounded like one of those easy-going guy we all know.
Axl Rose is possibly my biggest hero (though it doesn't mean I can't be realistic about his behavior) and it's extremely difficult to categorise him. He turns up late, but that's a universally known risk with GnR shows, and besides, how Rock N' Roll is it to complain about your bedtime :P. Lots of people call him money-hungry like Gene Simmons, but if that were the case why would he spend 13 years and millions of dollars working on an album when he could pump out material every two years and get a juicy paycheck every time? He's been described many times by friends, colleagues, fans and journalists as far more sensitive, vulnerable than the image he projects, lending credence to the idea that the character of Axl is far different from the man. The guy's a perfectionist, an occasional recluse, tempramental, bi-polar, but he's not a jerk by any definition.