Im a sucker for mind games. - I'll have an uneducated guess.
The cylinder would continually rotate, just due to the friction of water movement across the bottom. The roll direction would usually be "downhill" but this would also be affected by current.
The ballasted cylinder would only roll very slightly as the force of the ballast should vastly overpower the slight bit of friction from water movement. The most stable of the three (if enough ballast).
The keeled cylinder would roll more than the round ballasted cylinder due to the water movement force having the extra leverage on the appendage, although it would be the slowest roll.