As MM stated, there is no single best steel for everything. If there was, I'm sure we would see every knife being made of that steel or something very close. There are trade-offs made depending on what the maker is going for. The things that must be balanced/considered are:
toughness
strength
edge holding/wear resistance
ease of sharpening
price
price/performance
corrosion resistance
finish - some steel like S90V don't polish up nice
workability - how hard is it to work with


I think when you consider all of these things (except maybe price) Infi is a very good all around, well-balanced steel. SR-101 and SR-77 are also very good and while they score better in price, they lose points in corrosion resistance, etc. As I stated, there is always a trade-off for one thing or another.

Hope this helps. <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />