IM looking to buy another Canon EF lens soon, I have few bucks to spend what has anyone found to be the best bang for the buck in filters or ? I already have lens hoods and UV and Polarizer's. IM wondering what the rest of the colors filters are for. Would also like to by a 2x converter.

 

The answer depends entirely upon what you're trying to do with those filters.

For example, I've only used colored filters when shooting black and white film in order to, say, enhance clouds.