For the budget, Phenom x4 9950. If you are not planning to overclock, Phenom x4 9950. If you are planning to overclock, Q6600. You should wait for Phenom II 920 to be released on AM2+ platforms in about a few days and see what it brings first. Don't go upgrading yet. Phenom II 920 might bring some promising performance and price. Just wait a week more before you make up your decision.
Phenom II 920 will be definitelly cheaper than I7.
I have found 940 model for preorder in UK for £250 and Core i7 920 is ~£320. I expect PhII 920 to apear at about £200 in UK, which will be about $200 in newegg. (my opinion)
phenom 920 isnt that expansive at all. its just that some greedy retailers think they can get them selfs alot of money by making you think that its a core i7 920 and there for bust up the price. dont let these fools play games with your head and dont buy anything from there webstores they dont deserve to make money with these misleading tricks. phenom 920 should be available for around 170-190 euro and its indeed alot cheaper then the core i7 and for a complete setup you wil save a few hunderd euro and for the mere 20% preformance diffrence its worth it in my opinion. you can overclock the phenom 920 just as easy as the core i7 even more easy and at a much lower price. Phenom 920 dous not have an unlocked multiplier but you can easily boost up the base clock until a range that the hypertransportlink reacher around 2GHZ much above that will make can make it unstable so you could actualy underclock the HT bus abit lower if you want to go higher. i my self am considering to buy a phenom 920 over a core i7 too perhaps. because then i can have crossfire 4870 or 4870x2 for less then the cost of a core i7 system