D90 hands down, especially if you get the 18-200 VR lens so worth it and is a better lens compare the canon EF-S 18-200 (so disponting, no USM :mad2: ; no manual focus override without switching the switch to manual focus mode (unlike a USM lens)).
so you want to invest in good lenses ... the 18-200 is a must!!!

also Nikon lenses have the same body mount that means you can use them on all their cameras....unlike canon