Camera quality similar to Canon XSi?

I'm looking for a camera with similar specs to the Canon EOS Rebel XSi but for a little cheaper and maybe not so advanced. Any suggestions? I prefer Nikon and Canon brands.
The quality of the photos should come out to look SIMILAR like the XSi.

P.S. I was taking the Canon G12 into consideration, but it isn't much of an upgrade from the G11. I also figured that I might as well get a Nikon D40 instead since it's only thirty bucks more than the G12. But I'm not a camera expert and so I was hoping you guys could help me out.

MY BUDGET CAN BE NO MORE THAN $500.

Okay these are your choices for a new camera under $500 whose image quality is close to an Canon XSi.

Pentax Kx
Canon XS
Nikon D3000
Olympus E-420
Sony A500

The Nikon D40 is an excellent camera. The Canon G12 is also good but is a different kind of camera than the DSLR's you mentioned. It is a Advanced P&S shoot meant for people who want a camera with manual controls but in a small size. It is an excellent travel camera.

http://cheapdslrprofessional.blogspot.com/

I think you should go with Canon G12 10MP Digital Camera

* 10.0-megapixel sensor and the DIGIC 4 Image Processor combine to create Canon's HS SYSTEM for improved low light performance
*Shoot 720p HD video in stereo sound; HDMI output
*Canon's Hybrid IS compensates for angular and shift camera shake during close-up shooting
*5x optical zoom with Optical Image Stabilizer; 28mm wide-angle lens; optical viewfinder
*Capture images and video to SD/SDHC/SDXC memory card, MultiMediaCard, MMC Plus Card, HC MMC Plus Card (not included)