You didn't even mention what CPU you have
It depends
If you have something lika a pentium or i3 and can't afford a new motherboard and RAM stick with the LGA 1155 socket it is still a very aceptable platform in these days
If possible, get a 3470 or even a 3570 which runs at higher speeds and remember in editing or encoding an i5 is much faster
Although skylake is a better architecture it's more expensive. Furthermore, if you have a basic GPU it doesn't make sense to get a top of the line cpu