Let the hive mind of Engadget get that for you.
"I commonly need to boot a system from an external disc and take a snapshot of the host system. I also then need to burn a copy of the image to a DVD. While I can do it with two separate external devices, and two power supplies, and two I/O cables, it'd be nice to find a small dual-drive enclosure. It would need to have USB, eSATA, and FireWire. Either slim-line or half-height bay for the optical burner would be fine, and space for either a 2.5- or 3.5-inch hard disc. Any ideas?"
I bought it because of the feature set, particularly the sealed casing. (Also all of the same features in the Pentax K10D) I travel a lot so I was looking for a really durable model. Back in July I took it to a bunch of pyramid sites in the mountains in Mexico and it held up really well, took over 2400 shots in two weeks. It has image stabilization that actually works. The sensor cleaning system is becoming a standard feature on all entry-level DSLRs, but that's irrelevant because none of them work anyway. But your biggest concern won't be features -- it'll be the lenses.
You can get the K10D with the lens kit for under a grand, but keep in mind that no matter what entry-level you choose, you're going to spend well over that budget when you include good lenses. My first two lenses are a really nice Sigma 18-55mm macro ($450) and a cheaper Samsung 55-200mm zoom lens ($150). They've both given me excellent shots. If you want to get a do-it-all lens that covers the whole range, (as I will soon) expect to spend $400 or more. For example, the holy grail of all digital camera lenses, the Nikon 18-200mm VR, costs like $750... and you probably still have to back-order it.
My biggest concern was fewer lens options, but as Pentax expands its DSLR range that won't be considered an issue any longer. It's certainly not for me right now -- my macro lens in particular is very high quality and solid build. There are plenty of other options for Pentax mounts.
Although I've played around with the Nikons and Canons, I've never owned one myself, so I can't draw many comparisons -- this is my entry-level camera. All I can say is that I have no regrets about buying this camera -- I'll be taking it every time I get on a plane.
Oh ya, no matter which brand you choose, always get an extra battery and extra class 6 (high-speed) SDHC card.