Depends on your level of experience, you may want to start of with 450D or 500D for beginners. 40D or 50D is considered for advance amatuers already. More importantly, read up more and check your wallet!
I guess there are most of newbies like us who have to check our wallets more often than not. Like the advise given to me, consider room to grow for whichever unit you decide to get. Exhaust some time in researching the other brands as well.
I haven't made up my mind myself but for Canon, I'm looking at the 1000D or 450D. Good luck.
For what it's worth, here's some advice from a newbie to a fellow newbie
I compared the same models as you (also looked at some Nikons). The 1000D really is a very basic camera and for the price difference, I think you're definitely better starting off with the 450D. I would only recommend the 500D over the 450D if you intend to use the movie mode, otherwise there really isn't too much reason to spend the extra (the image quality of the 450D is actually crisper pixel-for-pixel as compared with the 500D). The 40D and 50D are a notch above newbie level and the 450D/500D should serve you well for quite some time.
I agree with Melbourne Guy. The 1000D is very beginner. The 450D seems to be good for a beginner.
My personal opinion is if you're not so serious, go look for the 450D, and that could save you enough to buy another lens. Otherwise if you're serious and want something that could satisfy you for a long time, go for the 40D. The 50D body alone would nearly wipe out your budget of 2000k and below.
The 500D is new and has a video function but that isn't really what anyone needs if you're shooting a picture.
First off, 10MP is more than enough for almost everything. Unless you're talking about printing to large banners (actually it's even okay for those).
You didn't mention your level of experience (with prosumer cameras, film cams, etc), so I don't know if you already have a preferred shooting style. If you're a total novice, you wouldn't really have one yet, so it's hard to tell which features will really matter to you.
The best bet would probably be to get some hands-on time with the models you are looking at, at a shop or showroom. Personally, I went for the mid-range Canon line (XXD series) straight away cause I prefer the control layout (incl the rear control dial) and the smaller XXXD series didn't really fit my (large) hands well. These might seem like small details, but they can become important over time! Ergonomics are a pretty personal thing.
If you're considering other brands and need lots of hands-on time, some of the showrooms have display models you can 'play' with e.g. the Sony showroom at Wisma and the Olympus showroom at Valley Point. I dunno if the other manufacturer's showrooms do the same -- they should.
Good enough for what? Mega pixel race is over, although Canon might need a few more days to notice. What is more important here is Look&Feel (go to the shops and have hands-on tests) and the question whether you are willing to take the learning curve into handling such a camera. No point getting a DSLR if you just want to snap. There are cheaper ways to get that. DSLR is a system of equipment and learning. The camera is not the only part, there are things like cleaning & storage, additional lenses, flash, tripod, bag, filters and much more. That's the reason why you should define your budget first, then see what fits in.
don't forget to factor in all the other accessories and needed items to get for your camera, dry cabinet, blower, filters, bags, cleaning cloth, hood, straps, and etc etc. they can easily amount to a bit.
I started looking at 40D until i went to see the camera in flash, it is slightly bigger & heavier compared to 450D which eventually i got it from the forumer here...40D is really for the more advance user...and 450D enough to make you feel like a pro anyway....
well, as they said all it true. My choice is go for 50D. It's seem crazy idea to have it but this is my idea coz last year i bought 400D as for beginner level and my first DSLR camera, then i bought 50D after canon launched 1 month later(Im satisfied with it) !! i found that it such a waisted money for me to buy 400D even it was good. so think about it if you are not going to change the body so soon, think a good one instead. So sorry if i'm wrong because this is just my idea and if you don't have a budget problem. Thanks