A Mac is a great computer,spec for spec against a pc it really is worth it. Besides, who doesn't love mac software, and os x lion software will be out soon. I recommend the 13 inch MacBook Pro.
Motorola Xoom is a large (10.1 in ch screen) Android 3.0 (Honeycomb) tablet. It is out NOW and is really cool. BUT if you are not willing to spend the extra money, then get the iPad 2. It will be out soon (Steve Jobs held a conference unvieling it today, March 2nd). BUT if that is to expensive for you get the original iPad. BUT if THAT is also too expensive, the Dell Streak 7 is an Android 2.2 (Froyo) tablet that is only $199 with a 2 year contract from T-mobile.