Canon essentially created the entry-level dSLR market with its first Rebel back in 2003, and has been staving off the competition since. Though the $550 list price has been significantly discounted off its original price when it was first released, the Rebel XS still holds its own against newer, similarly priced base-level models.
The Pentax K-x stands out from the crowd not only for its rainbow of body color options, but also for being the lowest-priced dSLR to offer HD video recording. With a list price of just $650, it bests similarly priced competitors by offering an 11-point autofocus system, a Live View shooting mode, and impressive sensitivity range (ISO 100 to 12,800 expanded), not to mention the 720p HD video recording mode at 24fps.
A step up in the entry-level category in terms of both price and features, the Nikon D5000 was among the first dSLRs to deliver HD video recording for under $900 when it first came out just over a year ago. Since then, the price has come down enough to make the D5000 a great value for the money (with a list price of about $750 with an 18-55mm lens).You'd be hard pressed to get a better combination of feature set, performance, and image quality (especially in low light) for the money.
If your dSLR budget tops out at a grand, you won't go wrong snapping up the Canon EOS Rebel T2i. It borrows some heavy-hitting features from its big-brother, the Canon EOS 7D (also on this list) such as the ability to shoot 1080p video at 30 fps, as well as at 24 fps and 25 fps. Like the 7D, the T2i gives you full autofocus as well as full manual controls while shooting video, and it uses the same 63-zone metering system as the higher-end camera. In fact, you won't find a more full-featured or higher specified camera for the price on the market today.
Though rumors are swirling that a successor to the Nikon D90 may be announced as early as July, as of this writing, the D90 is still the king of the midrange dSLRs. With a list price of $900 (body-only), geared toward photo enthusiasts looking for more flexibility and better performance than entry-level dSLRs or even pros looking for a lighter-weight secondary camera. The D90 is hard to beat at this price point, in terms of photographic ability (both image quality and performance) and its video capability is just icing on the cake.
Though it has some tough competition, the Olympus E-30 (which lists for $1,000 body-only) holds its own and also offers some appealing features, such as sensor-shift image stabilization and a tilt-and-swivel LCD. The E-30 was also the camera in which Olympus first introduced its creative Art Filters which add in-camera special effects such as the Warhol-esque Pop Art with over-saturated colors, high-contrast Grainy Film, and the self-explanatory Pin Hole Camera, among others.
Like the Nikon D90, the Canon EOS 50D is due for an upgrade and rumors of an imminent 60D continue to circulate. Until then, however, the 50D is still a rock-solid camera for the money, as long as you don't care about shooting video. With a slightly higher list price than the D90 and E-30 at $1,100 (body-only), the 50D does sport some higher specs, most obviously its 15-megapixel sensor, speedy 6.3fps continuous shooting, and a sensitivity range of up to 12,800 (expanded).
There's not much to dislike about the Canon EOS 7D, which lists for $1,700 (body-only), and there's a lot to love -- notably superior image quality across the sensitivity spectrum and super zippy performance, with a whopping 8 fps continuous shooting speed (particularly impressive given its 18-megapixel resolution). Add in the 7D's industry leading video capabilities (1,920×1,080 HD video at a full 30 fps and full manual control), and you've got a camera should rule the category for a long while.
Though it's starting to look a little long in the tooth in some ways, the Canon EOS 5D Mark II is still my top choice for a reasonably priced ($2,500 list, body-only) full-frame dSLR. Like the 7D, it delivers full 1080p, 30 fps video with full manual control (after a firmware upgrade). Another firmware update brought the video capabilities in line with the 7D's, enabling cinema and broadcast frame rates like those of the Rebel T2i.