Is the NZXT Kraken X60 worth the cash?

And are there any cheaper water coolers or regular heatsinks which would be a good alternative or have better cooling performance/$?

If you're looking for the best performance, the Kraken x60 up there. If you're looking at value, you'll want an air cooler. I'm sure you've heard of the Hyper 212, which is the best value around, but if you want something that's higher performance while still retaining a great value, I'd look into the Zalman CNPS14X. Just a massive heatsink with 6x 6mm heatpipes. If there is a con to it, it's that its quiet operation sacrifices some cooling performance, but that can easily be rectified with new fans. Either way, it should be a great value.