Here are my favorites (in order) and why:
1. Blueberry coveralls- Double gussets and versatility put this cover in the top position! Also love the higher rise and how they easily fit over fitteds.
2. Diaper Safari- love the versatility! Also love the higher rise on my long and lean little man :-) . They are also cheaper than Flips and work well over fitteds.
3. Flips- love the versatility! The rise is a bit short :(.
4. Best Bottoms - using them with just their inserts is awkward, but I haven't tried other options (YET) but plan to, so they might go up in the list.
5. Econobum- very basic, shorter rise...most likely will be outgrown by my son because of his height and not his weight.
All in all I have no problems with any of my covers, I just wanted to make a list of what features I like better :-) .