Teenyfits lasted here until last week- he's 12lb 15oz now (at 9 weeks) and we've gone on to BG aio smalls. These are great, and they were a staple when Ryan was little as well (from 1-16wks).
fitteds I used my xs oww for 3 weeks and then it was too small but loved it at first! Also the kissaluvs, xs sandies and swaddlebees. Now I like the Flexitots, small sandies, and a few random bits and pieces, but we mostly use the aios right now.