I use SwiftTwit and love it. It's no longer being maintained, so it's not going to change or get any better, but it does work pretty well now. The developers who made Swift were taken into the Hoot Suite fold, and so they just stopped working on Swift.

If you want something that is actually current and being maintained, Touiteur is a good one. In some ways it does more than Swift, especially if you pay for the premium version. But there were some basic features from Swift that Toitueur hadn't yet implemented, and I'm not sure whether they have yet. (Like saved searches, which I use extensively.) And I know UI is a very personal thing, but I actually prefer Swift's user interface. So I've stuck with that one. Unless twitter changes their API significantly again, it will hold up.

A lot of people do use and very much like Toiteur, though. So consider trying them both out.

Oh, and for what it's worth, I use NewsRob for reading my Google Reader feeds.

And, I use the same name on twitter... just sayin'.