i'm sorry but these aren't very good recommendations. please check out the makansutra web site or book for better ideas.
boon tong kee is very specific (chicken rice) and good but overhyped. prima has no local atmostphere at all.
here's mine
no signboard seafood
casa bom vento at joo chiat (eurasian cuisine) or dulukula (sp? dulukulu??) at bukit timah plaza for eurasian/peranakan
bak chor mee (check the makansutra web site recommendation
fishhead curry at banana leaf or apollo / sammy's curry at dempsey / komalas vegetarian south indian food
fishhead bee hoon at ah moy street (can't remember the name at the moment)
frog's legs at geylang
satay/ sting ray for the token tourist experience (optional) at newton.