Your mother! She just won't. shut. up. !!!!
Yeah, that's my lame-o comment for the day.
I guess it really depends on what kind of twitter user you are. I'm not into it too much so I enjoy the nice interface of Twitterific(FREE). Although, it lacks features that serious twitter users might appreciate. Twittelator Pro is amazing for what they charge you. There are also a few push options, but I haven't tried those yet.
I don't understand all the hype over TweetDeck though (the app version). That thing is so buggy on my phone! I just don't get it. When moving from column to column the interface just glitches out. This has happened with the initial release as well as the update. I can't really recommend that one.