Talking Back

I don't even know what to write or where to start. I expected talking back from Teen...and trust me, I got it and still get it but nothing in comparison to Seena. And she's 4, well almost 5 now. We fight almost every day and it's exhausting. Is it an attention thing? Is this normal, typical 4 year old behavior? I think I do a pretty good job of showing equal attention between the kids, she doesn't show any jealousy. I've been trying different methods of discipline; time-out, taking away the TV (or something), ignoring the outbursts, I've tried lowering my voice to whispering and I've even resorted to smacking her on the lips. This has only happened on a few occasions and it's usually been when I'm at my breaking point and she's been so completely and ridiculously out-of-line. I always feel horrible afterwards and I know it doesn't do any good, for one, the first thing she wants to do is go tell daddy - which then puts me in trouble and two, this only ends up with more crying. I'm not against spanking but I don't use it as a regular form of discipline. I know it doesn't work. So, I'm at a loss. One method may work one day but sure as day, it doesn't work the next. I guess consistency is suppose to be key. I'm trying. I've seen the best results when I take away the TV - which is actually probably not such a bad thing. Just a few weeks ago, Seena lost her TV privileges for the entire day in a matter of 10 minutes. I usually give punishment increments by the time of day - no TV until after lunch, no TV until after dinner - no TV at all. The poor girl kept at it and she lost it for the whole day. That was a tough one because I remember it was a crappy day outside too but I stuck to it. Tonight she lost her "show" before bed-time and that was the end of the world. She even promised to be good the rest of her life if she could just watch her show tonight. Can I get a guarantee on that?