Actually Gopher, Water Cooling kits are drip free, and have built in systems that stop anything going wrong.

As for water cooling:

If you send £200 ($450) or less on a water cooling kit, you'll get reasonable cooling (however they are very noisy these kits due to still needing fans).

If you spend £200-£350 ($450-$600) you'll get a nice water cooling kit, that's very quiet, and provides good cooling

Now, my opinion is that Water Cooling isn't worth it, unless you intend on spending on a high end water cooling kit, your not going to be getting good cooling for your money.

If you spent $500 on a good water cooling kit, you could get the same cooling on Air, with $50 (however that would be VERY loud cheap fans).

However, if you spent $100 on air cooling / acoustic matting / silent hard drive casing you could get an almost SILENT PC, for ALOT less - with equal cooling (perhaps 2-4C CPU temperature difference).