I am on a Powermac G5 atm, had it for just over 12 months, loving it. Parents just got a Powerbook G4, they are loving it, and are getting another one soon for mum, cause she likes dads too much and wont stop using it, lol! My only problem with a mac is the higher price than a PC, but it makes up for that in the time that I save while doing work, cause I dont have to worry about crashes and viruses (you dont need any anti-virus software for mac, cause viruses MUST be manually installed on mac, no program can autorun unless the user tells it to, unlike PC).
If your in for alot of work, and a little bit of play, go for mac. If you just wanna play games, and only do a little bit of work, go PC.
This is just my oppinion, so dont be afraid to deviate from it, or challenge me!
Have fun laptop hunting!