I know Velvia is a preferred film for landscapes because of its fine grain and punchy colours and have shot a few rolls.
I have been playing around with ASTIA 100F recently - bought 10 rolls off ebay for $90 (RRP $21 each!) and have yet to pick up a roll recently developed - will post any breath-taking images

i havent used Provia as yet, heard some good things about it.
JD