What kind of computer should I get?

Buying a new laptop 101:

• First important decider: Does it have the right size? Weight matters a lot if you are to haul your laptop with you every day. Make sure it has a weight that you can stand to haul along. Also make sure it has a size that makes it possible to toss it around.
• Second important decider: Can it stand a beating? Expect to use your laptop a lot while at DIKU. Don't go buy something cheap plastic-stuff because it will only last months. It is better to live off of noodles some more and get good stuff. You are not out for raw calculation speed, but durability. It needs to withstand that you get bumped into on the train and that you fall on your bike in the snow in the winter. There is also wear and tear on the laptop itself from normal use. You will be amazed how few manufacturers that actually build their laptops for 24/7 operation.
• Third important decider: Heat sink exhaust. If you expect to sit with your laptop in your lap and not on a table, it has to be built such that the heat sinks exhaust is not down in your thighs. Otherwise it gets uncomfortable as soon as you hit the courses that use Haskell...
• Fourth important decider: Screen, Keyboard and mouse input. You can't just go out and buy a different keyboard or screen for your laptop, so they have to be somewhat good. I'd recommend going for a full-size keyboard since they are nicer to type on. Also, if you can't stand a trackpad, don't buy the laptop with exactly that trackpad. If you want a trackpoint, buy a thinkpad (the red dot on Thinkpads - also called the "cat tongue" or the "clit"). Finally, if the screen is too small for your taste or has bad resolution then you are stuck with it.
• Fifth decider: RAM and CPU speed. It usually matters less. Go for lots of RAM first and then go for CPU speed. If you are to do lots of heavyweight computation, getting a fast CPU can help. The GPU of the beast might also matter if you do lots of image synthesis or want to play with hardware accel of computations. Get something with some cores though so you can get into the modern world of parallel computing right away.
• Sixth decider: Battery life. If you plan on hacking lots in places where power is not available (on the train, say) be sure to get a laptop that can work for hours without a power plug.

Recommended laptops are usually:

• Lenovo Thinkpads: Expensive beasts, but oh so worth it. The best keyboards on laptops in my opinion. They can dual-boot to Windows/Linux easily and Linux hardware support is friggin' excellent. They have nice heat profiles and they are work-horses. Their internal hexagon titanium skeleton protects them a lot.
• Apple Laptops: Even more expensive beasts. Expect software to cost money if you buy one. Slightly worse keyboard than the Lenovo. Slightly worse heat profile. But the chassis is one piece of aluminum and can withstand beatings quite well. May be slightly harder to get software to work on the OSX system which is reminiscent of BSD Unix.

Not recommended:

• Anything by Acer - The kings and priests of plastic.
• Zepto, when they existed - The prince and nuns of plastic.