daddypa
Schizo
Schlumphene
Schmack
Schmedl
Schmeichel
Schmitty the little kitty
Schmoo
Schmooze
Schmoozer
Schmuckie
Schnapps
Schnee
Schnee ("snow" in German)
Schnickles
Schnitzel
Schnitzy
Schnog
Schnook
Schnuggems
Scholastica
Schooner
Schputtie Butt-toosk
Schrodinger
Schrodinger's Cat (of physics fame)
Schroeder
Schuffalufagus
Schuler
Schultzie
Schuyler
Schwartz