I started out as a 8x8 scrapper and transitioned to 12x12. The last layout I did was 6x9 and I really like that size. I will continue to scrap 12x12 for my children, grandchildren, sister and nieces.....as for me though, I like the 6x9.
I mostly do 12x12, however my friends book is 8x8 and the grandkids school albums are 6x8. I also do a lot of boos in classes that are 6x8 as well so I am flexible.