I like Gerber onesies because they are very plain and go well under sleepers or dresses, etc. They are not too thick and therefore work well under other garments. And they fit fairly snug, which is nice, so that the sleeves don't creep up when you layer something over the onesie. The only thing is that they tend to run small as sized. We bought 9-12 months for our 7-month-old after we had some 6-9 month Gerber onesies that started fitting "just right" and seemed like they didn't leave much room for growth. Caveat: we use cloth diapers (bulkier), so we needed just a tad bit more length than if we were using disposables.