For optical printing, any of Ektar, Portra160 (Kodak) or Pro160S/160C (Fuji) will work very nicely and Ektar at least should give you a very smooth image at that size. If you're scanning or may consider projection, you must try Velvia (start with RVP50 even if only so you know you've been there, but the 100 is good too) and Provia.