My local Safeway carries its house brand of sliced Primo Taglio Reduced Fat Low Sodium Lacy Swiss (1 slice = 35 mg. sodium). It's usually pretty easy to separate the slices, so I buy it often and use it in sandwiches. Alpine Lace Reduced Fat Swiss is fairly low in sodium too (1 slice = 90 mg. sodium). Because it's a Swiss cheese, the thin slices are also easy to separate.
I've found that Swiss cheese has the lowest sodium content of any regular type cheese; most regular cheese has 170 mg. sodium per oz. or even more. You have to check the labels, of course, but most blocks of Swiss cheese have a sodium content similar to the Tilamook Swiss Cheese (1 oz. = 60 mg.) I often purchase. I'll even buy sliced Swiss from the deli counter after I ask about its sodium content. Look for lower sodium Swiss cheese blocks at your local grocers.
Our favorite cheese is Tilamook Sharp Cheddar (1 oz. = 170 mg. sodium). Obviously, I have to be careful using it, and I've developed a "work around." When I shred cheese, I use half sharp cheddar & half block Swiss. Doing it that way, I lower the sodium content considerably and the flavor is as good or even better. Another thing I do is shred cheese in advance and freeze he shreds.That way I can a sprinkling to any dish that needs a little visual "punch."
Safeway carries an unsalted cottage cheese. Unfortunately, it tastes like chalk all by itself! It's very good in lasagna, spanakopita, enchiladas, etc. If you like to eat plain cottage cheese, you might want to try one of these "work around" options. OPTION #1: Buy one container of the Lucerne No Salt Added 1% Cottage Cheese (1/2 cup = 45 mg. sodium) and one container of Lucerne 2% Cottage Cheese (1/2 cup = 410 mg. sodium). Combine the two containers and re-pack. Now you'll have a lower sodium cottage cheese (1/2 cup = 228 mg. sodium) that has some flavor. Not a perfect solution, but the no salt alternative is inedible in my estimation. OPTION #2: Buy one container of the Lucerne No Salt Added 1% Cottage Cheese (1/2 cup = 45 mg. sodium) and add 1/2 tsp. of Kosher salt; mix well. This will also give you a lower sodium content (1/2 c. = 180 mg. sodium). Again, not a perfect low salt solution, but, take my word for it, the no salt cottage cheese is dreadful on its own. However, it is just fine in any casserole type dish where it's combined with some robust flavors.
(For information about Sargento's new low sodium cheese products, check out this POST.)