What is best CPU for $100~$150 mark? Need it for heavy video editing and music, some internet browser. AMD & Intel
Depends, also the cost of the motherboard varies depending on the CPU/socket, so you should really give some more information...
If you don't want to play games on it then a Sandy Bridge CPU will greatly accelerate video encoding (between 2x and 8x) with it's quick sync feature (might have to check for compatible software) (also will only work on most boards if you don't plug in a seperate graphics card) Only thing is you'll want an H57 motherboard (look for B3 revisions to avoid problems with the 3GB/s Sata ports) which means you won't be able to overclock but for video encoding it will be much faster than an overclocked K series on a P67 board.
I was thinking of using something like ASUS M4A87TD/USB3 AM3 AMD 870 or ASUS P7H55-M PRO LGA 1156 on Intel.
If you already have one of those motherboards than great, get the fastest you can afford, but it looks like those boards won't give you anything in terms up future upgrades. P55 is going to be more overclockable than H55 if you're interested in that side of things. If you're main use is heavy video editing then it's probably worth the extra for Sandy Bridge (1155) though.
I see that you are in the US. MicroCenter has the i5-2500K for 179.99 right now. It's slightly above your price range but about a month ago I was asking myself the same question and I have not been disappointed by my choice so far. Also, if you spend the extra $29.99 you will be getting not only the best processor for 100-180$ but also one of the best processors available right now.
You wouldn't even need to pay the premium for the K version as it has an unlocked multiplier which is unly useful in P67 boards which have no support for the on board graphics and therefore quick sync. On the other hand if the K series is in a sale and cheaper than a non k series then go for it, it will have twice the on board graphics power of a non k series. Quick sync will be the same on either.