What is "The Best" U.S. Currency RegEx?

here's some stuff from the makers of Regex Buddy. These came from the library so i'm confident they have been thoroughly tested.

Number: Currency amount (cents mandatory) Optional thousands separators; mandatory two-digit fraction

Match; JGsoft:
^[+-]?[0-9]{1,3}(?:,?[0-9]{3})*\.[0-9]{2}$

Number: Currency amount (cents optional) Optional thousands separators; optional two-digit fraction

Match; JGsoft:
^[+-]?[0-9]{1,3}(?:,?[0-9]{3})*(?:\.[0-9]{2})?$

Number: Currency amount US & EU (cents optional) Can use US-style 123,456.78 notation and European-style 123.456,78 notation. Optional thousands separators; optional two-digit fraction

Match; JGsoft:
^[+-]?[0-9]{1,3}(?:[0-9]*(?:[.,][0-9]{2})?|(?:,[0-9]{3})*(?:\.[0-9]{2})?|(?:\.[0-9]{3})*(?:,[0-9]{2})?)$

I found this regular expression on line at www.RegExLib.com by Kirk Fuller, Gregg Durishan

I've been using it successfully for the past couple of years.

"^\$?\-?([1-9]{1}[0-9]{0,2}(\,\d{3})*(\.\d{0,2})?|[1-9]{1}\d{0,}(\.\d{0,2})?|0(\.\d{0,2})?|(\.\d{1,2}))$|^\-?\$?([1-9]{1}\d{0,2}(\,\d{3})*(\.\d{0,2})?|[1-9]{1}\d{0,}(\.\d{0,2})?|0(\.\d{0,2})?|(\.\d{1,2}))$|^\(\$?([1-9]{1}\d{0,2}(\,\d{3})*(\.\d{0,2})?|[1-9]{1}\d{0,}(\.\d{0,2})?|0(\.\d{0,2})?|(\.\d{1,2}))\)$"