To the original poster: If you want to get a young guy something properly mobile but is cheap and extremely potent with modern gaming, then my personal recommendation would be the Thinkpad W500 or T500 with Radeon 3650. The V5700 in there, despite it's age and ridiculous ATI heritage, still packs a punch with most modern games. And as long as you get one with a T9400 or better, it can do pretty nicely with Windows 7 or 8. A fully loaded W500 can also be loads useful, with a camera, fingerprint reader, turbo memory, and the WUXGA screen. I've sold two W500s to my friends(who before previously had current model laptops) and they really love the Ultrabay, rock solid feel, and the keyboard and touchpad. The first I assembled for $280, the other for $190. Windows is not included in that cost.
If he needs anything that's better on performance, then whatever you're going to get will cost more, or not be as nicely made. A T410 would be a good idea-the NVS3100M in that is really good for games as well. I believe that as with most teens, they're going to drop it, stack books on top of it, step on it while it's under a blanket on the floor, etc. I'd like to hear if you find something that has a more delightful balance between ruggedness and performance.
PC gaming is supreme, but expensive.
However, I think it's safe to say we have over analyzed this situation.
You can never give a scenario too much knowledge... well, actually, I suppose you can. But regardless, I am an idiot, so I must press on. You don't have to read what's below.
Gaming and laptops is, IMO, an oxymoron. Unless you are willing to spend the $$. A cheap custom build desktop with a $200 GPU will easily out pace most so called "gaming" laptop. A cheap Lenovo mini desktop can be had for $100 with an E8400 CPU. Add a $200 GPU and you'll have an entry level gaming system that most laptop will have a hard time keeping up with.
Getting a powerful cpu and gpu into a notebook and a cooling system to support them isn't an easy task, but you can do a lot with a desktop including liquid cooling systems and multiple GPUs
In my personal experience, it highly depends on how well the laptop is engineered. Because Laptop processors, or mobile processors, work quite differently... they dynamically change their performance in response to the thermal ceiling, and power available. This results in inconsistent framerates and performance during games and simulations. For example: Some CPUs run on full until they reach 100C, at that point they enter a "low-power state" where they undervolt or underclock to burn less go-juice and produce less heat. Most Desktops, in contrast, don't know a thermal ceiling, except to instantly shutoff when they get too hot. They just assume that the system builder has properly set up the cooling. Any throttling or tuning done to help a desktop's thermal profile on the software level is usually third-party stuff, such as on servers or workstation computers, or gamers for when a component overheats.
How well a laptop performs is highly dependent not as much on the CPU or GPU, but how large the thermal ceiling is. The more copper, more fins, the bigger the fan, the better the thermal ceiling. However this usually means more weight, and only gaming brings out the worst of a laptop's thermal profile. So most makers go for less weight and more efficiency.
Laptops with a small copper pipe and a single fan don't have much to dump the heat into-so they hit their thermal ceiling easier during gaming. Other laptops combat this problem by simply: adding more copper and fins(T4x and on do this), adding a more massive fan, or adding
more fans. So really-if you're looking for a mobile gaming solution, you want something supremely engineered and designed for CAD work(i.e, a Thinkpad) OR, you want something gargantuan or extremely massive(Alienware M18x, ASUS R.O.G.) the "laptop" that does this best by far is... you guessed it, a combination of the two. The Thinkpad W700. It's got separate CPU/GPU fans, which have fins spread on the sides and back relative to the fan, and massive heatpipes to the processing die. It blazes any task, including gaming, and because it's a Thinkpad, it's whisper quiet.
It is true, that in general with buying a laptop, the equivalent performing desktop is vastly cheaper. But it is the mobility you're paying for. And on the subject of using secondhand hardware,
yes, it is possible to obtain a cheap mini-desktop, cut a hole in the side, and plop a Radeon 5570 in it and watch it fly and the PSU sizzle, and do it all for just a few hundred, possibly even under a hundred. But a low-end W700 can be had on ebay for $300-$500, and my D900F, a gargantuan monster laptop that uses an X58 chipset and server-grade(Xeon W3570) CPU, only cost me $750, charger and Windows key included.
Trying my hardest to collect Thinkpads, but college and being broke kinda gets in the way. However...
701C, 760, 770, X24, T30, G41, A31p, T43p, T60/61 Frankie, Z61p, X60 SXGA+, W700ds
MEDESSEC
and yes. I am a bit of a lunatic.