good luck finding anything better for its price in comparison to its features...
from my experience, its one of the best cameras money could buy below the 950-1000 dollar mark. i got mine for 400. used they go for about 300-500 depending on whats coming with it. new they go for about 450-800 depending on whats coming with it.
plus, very user friendly, and arguably the largest selection of lenses are compatible with the camera. something nikon/canon can not say for their newer cameras...
not sure how the k-r matches up, but anything by pentax is really solid and does awesome colors, features, and prices.
Pentax K1000 - Cheap and effective way to learn photography basics, you could even get a reel/tank/chemistry and go a bit further into the whole process.
If you mean like old-school 35mm SLRs, then look for Pentax or Nikkormats. I had a good chunk of my photo class using Pentax cameras, and a few including myself used Nikkormats or Nikons once the 'mats were no longer being produced. There's minor differences between the two and I'm not sure which I prefer more since they're both reliable.
Any of those can be found for dirt cheap on Craigslist and you can probably get people selling em with extra lens and such as well for w little bit more.
I would hop down to your local Penn / Ritz Camera shop and get someone there to walk you through what would work best for you. You don't have to buy from them, but they will walk you through what would best suit your needs and in your budget and possibilities.
Also, these stores have regular free classes and workshops that get you started on the basics of SLR and how to tweak the settings of the camera to get the shots you want.
That's the best way to go about it if you don't have prior experience or someone who you know is good with a lens. Don't go to BestBuy or any of those stores, they will try to sell you the latest camera.
Oh and like most pro's will tell you 8.0 megapixel is plenty big for 90% of the people out there. Don't get fooled into the "more megapixel is better" slogan all the stores sell. That's also what the people at Penn Camera told me (as in 6 megapixel is plenty good for my needs). Anything beyond that, you're just eating up your HDD.