I freeze everything I can. I have frozen sourcream before, but mostly by accident because it gets pushed to the back of the fridge and then it freezes solid. My fridge is bad for this ever since I bought it. Most of the time just thawing it back out and stirring it up well does the job, but if I'm using it on items like perogies or baked potatoes I mix it up well with my mixer. Helps it get back to it's lighter state.
I don't buy dips most of the time, so I don't know if they freeze very well. I do buy cream cheese based chip dips or spreads and freeze them, mixing well after they have been thawed works really well and I find they taste the same as they were before frozen.
IloveAnnie, I have also frozen cream of mushroom soup. I prefer to freeze it in its condensed form than in actual soup form. I don't like the graininess of the made soup after it has been thawed.
My most favorite thing to freeze is cooked potatos. I either shred them up first or dice them, freeze them on a cookie sheet and then transfer them into ziploc bags once everything is frozen. This makes it very convenient when trying to cook meals in a jiffy or just wanting to add them in as an ingredient to a soup, stew or casserole.