A personal favourite of mine :
25psi boost, rwd and sticky tyres saw it hit 0-60 in 3.9 at Trax in 2004, not sure if it's still on the road any more though.
I love this one too :
As someone mentioned earlier, the myth that they pop headgaskets and are unreliable is down to them being owned by people who do not know much about them and turn up the boost without the supporting mods. I know several people who do many miles in their cars virtually problem free, a fair few recieve a beating on track days too.
I love R5s, there's just something about them, I dunno, call it character, but they certainly make you smile from ear to ear. They might not be the quickest or best handling cars around but they a awesome to drive (after some tweaks anyway).