Eclark;

If you have to go with with a laptop, then you want to look at a) system and video memory (if it has separate VRAM. Those that don't share sys mem), b) OpenGL implementation, c) Whether its an integrated GPU (like the AMD A series processors) or a standalone (like the Intel greaphics chip) The former can degrade the processor if you push the GPU hard enough due to heat, while the Intel will overheat the whole system if the airflow is badly designed or blocked

If you decide to go with a desktop (I remember you said you had no interest in building it), then make sure the builder uses 'white box' standard parts. Those are components built to meet the actual IEEE standards, so they are usable in any system that takes industry standard.

And add me to list of 'Avoid Dell at all costs'. They do their job, and are designed and built to force you to send it back to Mikey and Co for any maintenance or upgrading. As business machines they work, as personal units they tend to be a frigging nightmare to deal with.