"Phenom extreme" isn't any type of Phenom I have heard of before. Is it a Phenom or Phenom II? If it is a higher end Phenom II, it wouldn't hurt getting the 4870. However, the 4870 is the most expensive but the most powerful. The GTS 250 and the 4850 are roughly the same in strength, the GTS 250 is just a little bit stronger. The 4770 is the weakest card you have listed, but it is stronger than your old card.
Looking at it, all those cards are going to give you a boost in performance. A performance enthusiast would pick this:
HIS H487Q1GH Radeon HD 4870: $160 after mail in rebate
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161292
All the cards can play all current games adequately, so your choice will be based whether you want to play the newer games on high settings.
It's completely your choice, I have a 9800GTX+ and it runs games adequately, but struggles running newer games on maximum settings (ex. Empire Total War). But overall, its a very strong budget card.
I would buy the 4870, only because I don't want my computers out dating soon, I like keeping them for a while.
Its completely your choice.
EDIT: Then again, if they are all the same price, GO WITH THE 4870!!!