What are you going to use to crack passwords? John the Ripper (my fav) Cain & Abel, LCP, Rainbow Crack, Ophcrack, fgdump, pwdump6, L0phtcrack etc...
You can not just crack any password. I don't care how much time you have in the world or what application you use, Not all passwords can be cracked.
Do a simple google search on the subject if you don't believe me.
Well give some examples of some that can't.
just let me eat my dinner pot roast and mashed potatoes and corn on the cob with margaritas brb in 30 minutes.