I used BGS and AvEx.
BGS because its 100% online (even the mandatory classroom) and had a good price point. Also tthe mandatory revision classes are on a weekly rotation so you really never have to wait really and can go at your own pace. I didn't buy any manuals or anything in addition to the digital online course - didn't feel i need it as i had a CFI background.
Then i did all the AvEx questions. I did notice that about 5-10% of the questions on AvEx cover material that wasn't covered by BGS' online course. I dont know why.. maybe its in their printed manuals you can buy. Sorry i have no concrete example - its just my perceived observation.
AvEx is good. I love the comment section about it because it really does often give good tips and helps to understand some things, but AvEx does once in a while get it 'wrong' (thats where the comments help too). Keep hearing atplq is the best... i dont know anything about it, but BGS & AvEx prepared me well enough - i got a 90% average.