i was wondering what linux os would be good for my computer ive heard linux dont work well with the 64 bit version i have a intel i7core 720 quadcore computer toshiba satellite a505

linux works just fine on 64-bit. But your issue may be that a machine that new may not have drivers in the kernel shipped with whatever distro you use. Your best bet is to try out one of the most recent releases of a fast moving distro (i.e. every 6 month release) because it'll have a more recent kernel. You could try Ubuntu 10.10 (released this month), OpenSuse 11.3 from this summer, Linux Mint, etc.

You may not have luck with more stable distros like Debian (unless you try testing), CentOS, etc without recompiling a kernel.

notebook or desktop version my computer is a laptop

It shouldn't matter. If you use a distro that was released soon, it should have the best chance of working. I'm not saying 100% it'll work. You'll just have to try some out. Many have LiveCD's that you can boot up and see how your hardware works.