If you are prepared to consider second hand kit then you could get yourself a very decent body for not a lot of money and perhaps team it up with a standard 18-55mm kit lens as your starting point. Take a look at mpb.com --> they have Canon 40D or 50D bodies for not much over £100. Both are very decent cameras and take both standard and the much more expensive "L" series Canon lens. I have a 40D as a back up camera to my 5D MkII. I owned the 40D before upgrading but won't part with it as it's a very nice piece of kit. Looking at prices for a Canon 18-55mm F3.5-5.6 III you can get an excellent condition second hand lens for £49 so you could get a very decent body and basic lens (which you'd get with any new basic new DSLR) for just shy of £160. The best investment is always in good quality lens when your budget allows but it's a tough call for new lens with the exchange rate the way it is these days.
Obviously there are some risks with second hand kit but I've had issues with every new Canon camera I've bought so buying new is no guarantee either.
Sorry I can't comment on other makes as I've tended to stick with Canon.