Is anyone running Win7 together with a Linux distro?

I'm thinking of adding a Linux OS either as dualboot or VM.

I've no Linux experience so recommendations for a simple easy-to-use beginners version would be appreciated.

Here's the specs of my desktop:

HP xw6600 Workstation
- 2x Intel Xeon Quad E5440 @2.83GHz
- 8x 1GB FB-DDR2 @ 667MHz
- Kingston/Intel X25-M 160GB SSD [OS and Programs]
- 2x 1TB Spinpoint F3, RAID 0 [Data/files]
- 1x 1TB Spinpoint F3, backup
- Win 7 Ultimate x64

I've done quite a bit of research but ended up no better off than when I started.