I've encountered success with both the PET bottles that are popular and Grolsch-style bottles. The keys are to keep everything sterile and clean, and to keep the bottles out of stinky bottle syndrome lights (especially flourescent lights!). Keep in mind that smaller bottles will age faster than larger ones and are therefore good to try first, if you're impatient (as most homebrewers are). The advantage of PET bottles is that they are, for the most part, airtight and there's no need to worry about rubber stoppers. They just aren't as sexy as glass bottles.
In defernce to Uncle Bobby, homebrewing can be a cheaper alternative to everyday beer drinking...but cheap does not need to be a bubbly liquid with booze in it. I've made great homebrew, and some rather nasty stuff that I kept to myself. This is the process of trial and error, and of education. I think that the more you learn about GOOD homebrewing, the better your product. I think that most of us aim high - great beer at great prices. If something sinks for some technical reason, we can probably drink the result with sombre tones and will learn from the experience. The key is to not just make booze, but beers that you would proud to serve your pals. It is fun, stinky, labourous, intense, jovial and entrenched in a love of beer. Good luck.