I use a laptop for gaming. I have to.. wife's pc broke and she took my desktop over.. But.. I love my laptop. I have posted a list on other forums of over 100 modern FPS games this thing playes well on either medium or high settings. It is a Compaq cq61 with a single core AMD Sempron II 3.0 mhz processor ( dual processors are way overrated for gaming, as most games dont make use of them anyway) with 4 gigs of ram. It has a 366 megabyte ATI Radeon 4200 HD video chip that can use shared system ram for a total of 1.6 gigabytes of video mamory. ( people also say shared video ram sucks, thay are only half right - shared video ram works awesomely if your not trying to run lots of other applications in the background. This thing cost me $ 350.00 at Wal-Mart - about the cheapest new laptop you can get. came with 2 gigs of ram, I added 2 more gigs for 50 bucks. Total 400.00 U.S dollars.
On it I play Oblivion (Nehrim) on medium settings, Fallout 3, Fallout New Vegas, All Thief games, Splinter cell games, Two Worlds, Gothic 3, Half Life 2, Doom 3, Singularity, Call of Dudy Modern Warfare 1 and 2, GTA San Andreas & GTA 4, ( low settings for GTA 4) Crysis 1 and 2, Far Cry 1 and 2, all the Stalker games, the Precursers, White Gold 2, borderlands, ( and a bunch of older games like Morrowind and deus ex - you name it, this thing plays it well. Most games that came out this year I play on medium settings and thats just fine with me. Most other games that are at least a few years old I play on high settings. I say, grab a laptop with a good video chip and try it out - don't listen to the crowd. Only games I really have any problem with and have to go to lower than medium settings are console type games that were not optimized well for PC.
Beats any portable gaming system and any console system hands down, is portable, more flexable than those. In my book it's a win win.