I think it might help if we knew a little more about what you want as well.
On the desktop side, you could easily afford a decent Core i7 (quad-core) system with at least 6GB of RAM. Hell, even my $550 i3 (dual-core) Gateway with 6GB could take an i7 CPU (which I could buy fairly cheaply if I were inclined to upgrade).
On the laptop side…. it gets complicated and pricey if you want something that can do video editing even half as fast as a cheap desktop.
I won’t get more specific than that because I can’t. See, it’s not even Thanksgiving yet, so a lot of places haven’t announced their Christmas specials yet. You might be better off waiting until we’re actually a little closer to wintertime.