I know the ones people recommend on here are good, but they are also a bit costly depending on how you look at it...
For me, Toyo T1-R's have always been a decent choice at a decent price.
I actually just fitted 2 Falken FK452 tyres to my 18" and they came in at £163 for 2 tyres fitted & balanced which was more up my street price wise! Also they are not a cheapo tyre, they are decent enough.
So much so, that i'll be replacing the rear 2 tyres next month with the same ones.
Mac Sams tyres are a good site check them out if your interested as they show your local fitting centres etc.