I see that your spechs are from best buy, are you planning on buying from them?
If you are then talking to the sales reps can help some.
I perfer AMD processors, so I would lean toward the emachines, but then I don't especially like compaq or emachines... I would buy a acer, IBM, or systemax, if I was looking to buy a laptop. (currently I have a IBM Thinkpad)
The other thing that I don't know is if you are restricted to the Best Buy store or if you can purchase online.
Within your price range, I'd also be looking at this one:
Its about the same as what you have, but it combines the good from each laptop.
The Acer has:
512Mbs of ram, the same as the others, however, the Acer has DDR2.
a 60GB hard drive, so you can hold all your games,
a 3200+ processor, faster then the other two. 512 L2
15.4" LCD TFT screen
The only thing I'm not sure of is the graphics, the Acer has ATI Radeon Xpress 1100 and I'm not sure how this compares to the Intel Graphics Media Accelerator 950 or the ATi Radeon Xpress 200M . I am a Nividia GeForce person, not a ATI so I can't comment on the Graphics chipset. But then there is a review that was dated 9-1-2006, (this month), that said it could play modern games.
Plus the Acer is $499, after mail in rebates. ($599 w/out). So basically the same price as the others. Plus, if you want to use tiger, I have a $20 off $200 purchase coupon that you can use. I'm not using it, so I don't mind giving it out. just PM me for it if you want it.
But from your choices, I would lean toward the emachines, I hear the Celerons eat up battery quickly.
Hope that helps!