Friendly works well, the ads are small if you don't want to pay for the pro version (what is it though, like a buck? It's one of the cheaper apps).
If it's jailbroken, full force makes the iPhone app look great, looks like it's a native iPad app. Otherwise, Friendly works fantastic. Flipboard looks nice, but I find it to be limited and it never wants to update correctly or post comments, maybe it's just me but all I can ever seem to do is read, not write.
Friendly is just a skin of touch.facebook.com, however, which I think is why Facebook hasn't released an iPad app, for the same reason they don't have a Mac or Windoze app, they intend for you to use your web browser to access facebook. You might just like pointing safari to touch.facebook.com
-John