I am going to be buying an iMac, it will be my first mac. I generally have safari, iTunes, and CS3 open at once, and some very light gaming that will run on pretty much anything with a GPU. I'm trying to decide between the 2 20-inch models... I would upgrade to 2 GBs of RAM on the base model, because it only comes with 1 GB. Will I experience any lag on the base model that I would need the top 20" model? I'm on a 1.8 GHz sony laptop running windows xp right now, with 1.5 GB of RAM. HD space is not an issue for me. Thanks for your help, very excited to enter the mac world.