I found a pretty heated forum on line about this subject and was taken aback at how strong some people feel about this subject, so I thought I'd toss it out in here because I actually know you people and it's just not as fun watching strangers scream at each other. :P

I don't know, I've only been in Corruption, and have yet to enter a Crimson world.

(ugh I hate those "Soul Eater" things, and those giant worms that keep flying through the caves, they're so damn annoying :P)

I always liked the crimson more, just cause of the cooler armor.

If your world has Platinum you won't get Gold and the other way around. Same with Copper/Tin, Iron/Lead and Silver/Tungsten. For Hardmode, the alternate ore pairs are Cobalt/Palladium, Mythtil/Orialchum and Admantite/Titanium.

As far as the thread topic goes, I prefer Corruption. If only because it's the classic "evil" biome.

I prefer Corruption because that's what I grew up with (dang young whippersnappers and your newfangled Crimson!), but I have to admit that the Crimson is just flat out more interesting, especially once hard mode hits.

Go for Corruption!

I'd say Crimson AND Corruption.

What I do is seal corrupted/crimsoned parts of the map (to stop spreading). Then I seal a different part of the map to contaminate with the other biome. The Clentaminator is very useful for this.

Once I have enough NPCs in my base (to reduce hostile spawn), I Hallow the area around my base.

I enjoy both for their different representations of forms of darkness. I've played a fair amount of playthroughs with the Corruption and Crimson and I prefer the Corruption slightly more.

Partially because, it was the only "dark biome" available before the 1.2 update so I played with it more. The corruption enemies are interesting and I enjoy how its bricks are a type of "ebon". Purple is also a color closer to true darkness than red. Though both can look dark when put with black.

There's also that cursed torches and cursed flames overall are more interesting to look at than Ichor.

I prefer the crimson, personally. Pre-hardmode there's a lot more enemy variety, and post-hardmode you get Ichor Torches, which I vastly prefer to Cursed Torches. They put out a better quality of light and are brighter to boot. The flesh furniture is also pretty amazing, and is particularly interesting because the meat grinder chops up crimstone to make flesh blocks. So what is crimstone, exactly?

tl;dr corruption of form is more interesting than corruption of spirit.