We go to Dr. Pelina on Buel Ave & Hylan. He was my doctor from when I was 10 years old. Dr. Joseph Castellano, right by Kelly Blvd and whatever that street is going to the mall. The one that comes straight from Snake Hill, parallel to Rockland. I've also heard good things about Comprehensive Pediatrics and they have 2 offices, one out by Target and the other by Hylan Blvd and Richmond Ave.
Dr Abbodante. She is near Slosson Ave. She was my pediatrician from about age 14 til 19 as well as 3 of my siblings. My sister now uses her for my 4 year old nephew. She is very thorough and my mother took me to her after another doctor failed to recognize how serious my cold/cough was at the time.
I don't live in SI anymore but if I did that is where I would take my baby.
I take my almost 3 month old DD to Gabriel Pediatrics on Richmond Ave. This SI office is relatively new, but they have a Brooklyn office that has been around for a while, so they are established.
I like that they have separate well-visit and sick waiting rooms. Wait times are not too bad. They are open Mon-Sat. Mon-Fri they take sick walk-ins for a few hours in the morning. Saturdays are appt only, but for well visits where I schedule about 1 month in advance, I have no trouble getting in on a Saturday. I don't go to just one doctor there, my DD has seen about 4 of them so far and I have no complaints about any of them.
And for the record, they are close to the mall (corner of Richmond and Eton Pl, close to Victory Blvd).
I 2nd Gabriel Pediatrics - they're wonderful.
There's only one doctor there that I'm not crazy about but I just don't schedule appointments with her. You should schedule a visit with a few pediatricians to see who you are most comfortable with. Dr. Villaverde on Victory Blvd. is also very nice.