I personally hate everything with the name "Dell" on it.
But, a suggestion for a gaming pc, or any pc if desktop is build it.
If your trying to get a "gaming" laptop, thiers no such thing. Yes thier are good laptops and the SLI laptops and such but thier not fit for years to come, they will eventually be outdated compleatly and upgrading is incredibly expensive. Desktops have so much more for them.
Aside from my laptop and dell bashing...
Minimal what you want:
Duo-Core processor
Atleast 2GB Ram
Video card w/ 512MB [Id recomend a 8800GT]
Windows XP
I have a budget build as such that is about 750$ But its + anti virus and everything I could think of.
High-End build
Quad-core Processor
16GB of ram
A board that will support 16GB O.o
A board with 3 PCI x16 Express slots
3x EVGA 8800GTS in a triple SLI
Windows XP Pro x64
My recomendations of brands I have had good times with:
Hitachi hard drives
Kingston ram
Gigabyte boards
nVidia video cards
Microsoft Operating systems [Who else

]
Intel Processors
What I have heard is great for gaming;
Solid-State drives [ I dunno ?? ]
Any 790i board [ Strong disagree ]
Ubuntu [ erm.......]
Ram isnt important [ erm, ram timings? ]
amd processors [ Ok, ill give you the unlocked multipliers, thier more common on amd ]
ATi vid cards [ ??? ]
'Tis up to up to you.
Good luck