I recently purchased Cyberlink PowerDirector Ultra 64. Simple to use and pretty slick. Normally it retails for around £80 but I managed to pick a genuine copy for £25 from eBay in the US.
Suggest you go for the 64 bit edition as it uses all the RAM and processing cores your PC has to offer.
I use it with the digital footage I take with my camcorder and it happily edits and processed 1080p footage without a glitch. Suggest you check out Cyberlink's website to get the full low down.