My vote goes to Tweet Lanes. It looks good and follows the Android design guidelines. Very fast. My favorite feature is the ability to easily switch to and from different lists. Also a plus is that it remembers where you left off and shows you a count of unread tweets above your current position.
On tablets my vote goes to Plume, especially if you use lists to manage Twitter. On the phone side I agree with the below Tweet Lanes looks amazing and works well. Also Carbon is still rumored to be coming so keep an eye out for that.