Best hand held by far!
I own a PSP and Nintendo DS. Since buying my DS my PSP has been gathering dust on my shelf! The PSP just has no games that myself or my girlfriend like (LocoRoco being the sole exception) , whilst the DS has hundreds. We ended up buying a second DS for my girlfriend and now, two years on, I'm planning to replace mine with a shiny new DS Lite (nothing wrong with my original DS just want the much better screen on the lite for those sunny days!)