It depends on what types of games you want to play, thier requirements and how much money you have to spend. If you want all the bells and whistles and absolutely MUST have every game on all high settings with framerates above 60 (which is way overkill for fluent video that is standard as 25 fps anyway) then you can spend a lot of money on a ( here comes the marketing catch phrase) "gaming laptop".
I have a gamng laptop - I use it for today's games. It will play any game out today very well and it only has 336 MB for video ram. On an onboard chip. On a machine bought at wal-mart for $350.00. Granted, it uses shared system memory up to 1.2 gigs for video ram. I have 4 gigs of system ram in the machine. Most games I play on medium settings. XBox ports run a little worse than games optimized for PC so I have to turn down some settings to low while keeping others at medium. Things like HDR, Bloom I may have to disable depending on the game. All my games play very well, fluent. FPS is just a number for wanna be geeks. If the game is playing at a fast rate of fluent video for you it matters not if the FPS number is 30 or 60. I don't know what my general FPS is, never checked because it is meaningless as long as the game plays well. I get the experience of immersing myself in a great game with great graphics with no slowdowns.
My point as you can see is much of the info out there is simply hype to sell more stuff and people buy into it. It's not needed if your on a budget and still want to play games nicely. If you have the money to burn and you want all high end stuff thats fine too but never let anyone tell you you have to have a high end "gaming laptop" to play good games well.