Edited: just saw it was a very old post ... never mind, could still be useful?!
I can (and many others do as well) recommend the Stokke high chair. It's fairly pricey but I had mine for 6-8 years now. First of all it blends in nice with the furniture, it's not bulky, plasticy, etc. They learn to sit at the table straight away and it grows with your child. My 6 yo twins are still sitting on it, and plenty of room to grow. They don't consider it a baby chair at all. It just gives them easy and good access to the table, allowing you to enforce good table manners.
I also had the Fisher Price Healthy Care booster seats, which were great for travelling, outdoors, etc. Can highly recommend especially with limited space. Connects to your normal chair.
Would not recommend IKEA. I know many people rave about it, especially because it's so cheap, but I found it too light, too unstable and the legs are really pointing out too wide in order to give it some stability, but therefore takes up way more space than needed, plus I kept tripping over those damn legs. Had one for outside. It's easy to clean and cheap, but that's about it.