Basically any laptop with a 4th Gen Intel Processor (i3,i5, or i7) works fine. Look for intel HD graphics 4000 or above. They are actually blazing fast despite being integrated graphics. Battery life boost from Intel is nice as well.
. Make sure laptop has 4 to 8 gigs of Ram.
I don't recommend a laptop with dedicated graphics because
1. They will cost more than your budget.
2. More than likely the battery life trade off will be horrid (Crap Battery Life). Only exception would probably be this
If you decide you want more "power"/dedicated graphics, I recommend a desktop.
This time around. I recommend a system powered by a AMD processor. AMD has the best price/performance ratio.
You could easily make a budget desktop with $600. As with laptop make sure to get 4 to 8 gigs of Ram on desktop.
Get a Nvidia or ATI video card. You can this
use as a reference as to which to choose. From 1,100 mark and above.