I assume you are reading this because you have a legitimate reason to be cracking passwords (to ensure your infrastructure is as secure as possible, of course!). Over the years, I haven’t really had to use online password cracking but I did do some Windows NTLM hash recovery in the past and had a great experience without paying (albeit I had to wait a few days). Here are a few sites offering this service. Be ready to pay to get a result quickly..more will be added as I find em’:
loginrecovery.com – Great for Windows password hashes! Get the SAM file using their utilities or your own (a linux boot disk) and submit it. Wait a few days or pay a pretty low price to get the result in only a few minutes!
cloudcracker.com – This one is unique in that they support other methods of password cracking like WPA, SHA-512, MD5, and MS-CHAPv2!!! I haven’t yet used it but it seems you will have to pay either way you go. I would assume this one is pretty fast since they seem to charge quite a bit. For some interesting articles regarding different hashing methods, check out their informative blog.