Kevin Sussman as Stuart Bloom
Kevin Sussman played Stuart Bloom, the owner of the comic book stores which became a frequent haunt for the guys in Season 2. Although he wasn't a central member of the group, he still popped up fairly often. Kevin Sussman had a decorated acting career far before he joined the cast of The Big Bang Theory, having performed on shows like Ugly Betty and Wet Hot American Summer: First Day of Camp.
Lindsey Kraft as Marissa Johnson
Marissa Johnson, played by Lindsey Kraft, was the wife of Penny's ex-boyfriend, Zack Johnson. The pair met with Leonard and Penny and asked Leonard to father their child due to Zack's infertility. Lindsey Kraft has appeared on Living Biblically and Grace and Frankie.