Al
The first RoboShack owner, Al gives you the Heli-Pack on planet Kerwan. He's a big dude, but also a big nerd.

Al returns in Up Your Arsenal to join the Q-Force as a Master Hacker. He's also the source of several vidcomics and a few zanny lines...including some rather flirtatious ones thrown at Helga.

Bob
The second RoboShack owner, Bob gives you the Thruster Pack on planet Pokitaru. He taught his "idgit brother" Al the tricks of the trade.

Ed(wina)
The third RoboShack owner, Ed gives you the Hydro Pack on planet Hoven. She's absolutely ga-ga over Clank the "li'l angel", but she finds Ratchet to be a bit of a jerk.