In the last couple of months my grocery store has started to sell Farm Raised Salmon and separating it from "Wild" Salmon. Any difference in cooking these two that I should be aware of?
Following up roux's answer (that wild salmon has more flavour, which is true): presumably you'd buy the more expensive wild salmon to enjoy that deeper flavor. One thought is that the deeper flavor will support more additional tastes / seasoning (and it will). Another thought (which I prefer most of the time) is that the deeper flavor should be enjoyed for itself.
So, when cooking the wild salmon, use techniques that preserve the salmon as much as possible 'as it is'. Sashimi, if you're certain of the quality / hygiene, would be the ultimate expression of that.