What a good question to ask! I would not be without many of Paladin's (
http://simwardrobe.com) 'fixes' and objects, because they really improve OFB's silly little annoyances.
I also have an object I can't live without (it's an open/closed sign with custom meshes that adjusts if you are placing it on the floor, counter or wall (normal default for maxis signs)), but I can't find it at the moment sorry!