Which digital SLR canon camera is best?

1) EOS Rebel T21
2) EOS Rebel T1i
3) EOS Rebel XSi
4) EOS Rebel XS

and add why, also if uve owned any of these!
also, do you think nikon is better than canon or vice versa? Please include reasons!
I LOVE PHOTOGRAPHY!

This easy, the t2i is simply the best by far. It features 1080p movie, an 18mp sensor that is adopted from the 7d, very fast af system, good high iso, very good battery life, and the best screen ever on a camera that is less than 3000$.

Definitely the T21.It's higher resolution than the others, and offers better options, like HD video and more accurate metering.

I prefer Nikon for entry-level cameras. The entry-level Canons (especially the XS and XSi) just feel fragile and cheaply built. For professional-level, Canon is way better. They shoot faster and have clearer, brighter lenses. From the list of cameras you posted, it looks like you're looking for a more entry-level dSLR, so I would recommend a Nikon, specifically the D90, but the D3100 is also a very good camera.

Go with Canon EOS Rebel T2i 18 MP CMOS APS-C Digital SLR Camera
18 Megapixel APS-C CMOS sensor
DIGIC 4 processor with ISO 100-6400 (Expansion to 12800)
Continuous shooting at 3.7fps
Full HD movie recording with manual control and selectable frame rates
7.7cm (3.0") 3:2 Clear View LCD with 1, 040k dots
iFCL metering System with 63-zone Dual-layer Metering Sensor
Quick Control screen to change shooting settings
Exposure compensation +/-5 stops (although viewfinder scale is still +/-2 stops)
http://www.amazon.com/...0035FZJHQ/
http://rover.ebay.com/...86.c0.m282