Which brand Radeon HD 5970 would you recommend?

I'd go for the XFX Radeon HD 5970 Black Edition - double lifetime warranty for a ~$719.99 card is a good idea.

What does the "black edition" mean?

What does double lifetime mean (lol). All the cards are pretty much the same if they are based on the standard ATI design. Differences in custom cooling or factory overclocking separate the non standard ones from each other. If you are buying one based on the ATI standard for clock speed, memory speed and cooling solution, get the one with the best price, warranty, and perhaps promotional features. You might look at the customer reviews for reliability on sites like newegg. But as to performance they will all be pretty much the same.

Just a suggestion, if you can purchase locally it might be the best way to go. For example, locally I have a retailer called Memory Express. With anything you buy there, first off they take care of RMA. And better yet, for a small additional charge they give you the Internal Product Replacement plan and will replace your part right then and there if it's defective. I had 1 dead pixel in my first monitor and it was replaced with a new one in about 10 minutes (9 of which was me standing in line lol). And then I burned out an MSI P55GD65 mobo trying to overclock, and again got it replaced for free with an ASUS P7P55D PRO since they were out of the MSI boards. Anyway, just a tip... locally can be much better than newegg.

As for brands, when I had the mobo issue the tech told me that they've actually been getting a lot of MSI products in for RMA recently. I don't know if it's mostly been mobos or what but I just don't think it's a good idea to get MSI at this time.

HIS, Sapphire, XFX are all quite good/reputable. Unfortunately I don't really know how they are for RMA/technical servies.

I've been to just about every single hardware store in my city, not a single one of them sells the HD 5970.

Off-topic, but whats the highest settings an ATI Hemlock can play Crysis on with a playable framerate?

Black Edition normally means it's overclocked a bit, however with the HD 5970 XFX has not factory overclocked this card and instead provides a tool for you to help you overclock with the Overvolt tool. Double lifetime warranty means that if you register the card within 30 days of purchase, that card has lifetime warranty and if you sell it to another person, he/she will also receive lifetime warranty from XFX.

The HD 5970 can play Crysis Warhead on maximum settings with 2x AA @ 1920 x 1200 on trubitar's video, this was at 50 FPS I think.

Any overclock of the HD 5970 would almost demand aftermarket cooling. There aren't many air coolers, but there are many water cooling blocks for that card. The HD 5970 is known to run very hot (around 88 *C during intense gaming) but still nowhere near as hot at Nvidia's GTX 480. Most of today's graphics cards are designed and engineered to withstand very high temperatures.

Are there any high-performance aftermarket air coolers for the HD 5970?

Was trubitar's video playing Crysis on all "very high" detail spec? What about motion blur? I don't much care for motion blur, I often disable it because it makes the game look like you're on drugs. It can have a major impact on your framerate. If it is disabled, I would imagine this would help a lot.

For some reason, Crysis Warhead looks better, and runs smoother than Crysis both on identical settings and resolutions. Why is this?

How will the HD 5970 handle future games like Crysis 2, and Deus Ex 3?