Personally I favoured all in one singlet bodysuits to actual singlets - it is nearly impossible to keep anything tucked in and the all in one suits prevented bub from getting a cold back.
Flynn spent the first 4 months of his life in grow suits - I would say anything else is OTT. I agree a few nice outfits are good to have, but try and make sure they are easy to get on and off - most bubs hate being dressed and fussed with (though that said Flynn was like a little doll and let me dress and and undress him to my heart's content - it is only now at age 1 that he complains!)

ETA Misty that is so right about things looking good on the hanger but not on bub - now much looks "god"when you can't hold your head up LOL!!!