The Digital Rebel was my first digital Slr, which I bought back in 2003. It changed the way I practiced photography. But five years and thousands of shots later, I bought the Canon 30D, which worked wonders on my style of photography. I was planning on waiting for the 50D in 2009, but decided to go for the Rebel Xsi - 450D which I got just a few days ago and have been using since then. I took nearby 650 shots under distinct conditions and using a range of lenses from Canon and other brands. I can probably consider it as my top Slr camera and here are some of the reasons why:
The camera build is light yet feels very well built. The buttons on this baby are distinct from those on the traditional Digital Rebel and 30D; the buttons on the Xsi are more tactile and has a resounding click when pressed. The Digital Rebel Xsi has a 3-inch Lcd with 230K pixels, which makes the images look great on playback but experiences a diminutive delay when zoomed 10x before the images are loaded and displayed fully. The delay is probably not that noticeable to others, as I only noticed it because I was able to compare it with my other two lower-resolution Canon digital Slrs.
Canon 30d
The Lcd viewing angle is excellent, which is probably nearby 160-170 degrees vertically and horizontally. The Digital Rebel Xsi also has a status screen separated from, and located above, the main screen of the Lcd. This arrangement works for me because I'm able to see all the settings on the back screen. There are also two features that the Xsi has that used to be missing in the Digital Rebels: flash exposure recompense and spot metering. These for me are foremost features because they make the images more "complete" and compelling.
Aside from the usual 2-second timer, the Xsi now has a customizable timer function which allows the camera to count from 10 seconds then capture successive images as specified by the user. As for the Iso values, the Xsi 450D has five values to choose from: 100, 200, 400, 800, and 1600. Higher Iso values makes the camera more sensitive to light, which makes it inherent to perform faster shutter speeds under unavoidable lighting conditions. If you're not customary with Iso settings, you can opt to use the Auto Iso function which automatically sets and matches the Iso and the cleft to ensure allowable exposure at unavoidable shutter speeds.
The Xsi 450D has tons more of other great features which are development more and more users hail it as one of the best Slr cameras, if not the top Slr camera, ready today in the entry-level arena.
Xsi 450D - Why Many reconsider it the Top Slr Camera