Silva- hasmommyissues

That one pretty much writes itself.

Gary- honeytoes

A name he jokingly suggests he can be referred to.

Arnold Rothstien- dentistwithether

Thats what Gyp Rosetti calls him during Nuckys new year party in the season 3 opener

Steve Newlin- Praisehislight.

The name of his tv phone in show. That one isn't as imaginative as the others.

and finally Jim moriarty - jimfromit

Its kind of a play on the whole "I enjoyed playing Jim from it" line from series 1