So far I've tried three: Aldiko, FBReader, and UB Reader. All good, all flip smoothly, all let you customize text size and style.
A few differences to bear in mind:
Aldiko lets you customize bookmarks. OTOH it has trouble with a few files; one file I downloaded from Project Gutenberg would not display on Aldiko past the TOC; the other apps had no trouble with it.
UB Reader won't let you customize your bookmarks but it will let you customize your shelves. It also uses the least memory of the three.