Low Fat or Full Fat items???

Usually the low or no fat items replace the fat with salt and sugar. So it would depend on your goals. I restrict sodium and carbs so I limit the reduced fat items that I consume because of that. Some items like sour cream there is only a minimal difference so I opt for light. Some like salad dressing there is a huge difference in carbs and will go full fat to not have those extra carbs.

I always read the NI of all available (full, light and no) to see which one fits my personal goals better.

I go full fat. Fat doesn't make you fat and if you are within your calorie goals why not. There is no benefit to eliminating fat from foods like yogurt or cheese. The whole lowfat boogieman from the 60s and 70s has been debunked.

THIS!

I would say it is better to have both in your arsenal. If calories is not a problem for this day, and you are meeting your other goals, then eat full fat. If you need more protein, or just don't have the caloric headroom, then eat low fat items.

Although there is nothing inherently wrong with fat, I believe most doctors agree that you would be better off substituting as much Saturated Fats as you can with Unsaturated Fats.

Your body does need a certain amount of fat (especially the right kinds of fat)... So don't cut it out completely.

I'd suggest that you get into the habit of reading the labels so you can see what the ingredients are. I tend to buy reduced fat dairy as its not too hard to get relatively unprocessed versions of these. Some light versions (like peanut butter) are just nasty - they load them up with lots of starchy fillers to replace the fat and I'd rather eat a bit less of the real thing.

In general, my approach to food is to keep processed stuff to the minimum, so I can see exactly what I'm eating, then I choose how much sugar and salt and other stuff is added rather than the manufacturers.

Reduced fat foods often have more sugar or something like that to improve their flavour, but that's not always the case. Check your labels to see what extra nasties have replaced the fat!
I also read somewhere that often your brain tricks you into eating more of low-fat items. Say you eat a low-fat yoghurt. You're more likely to go back for a second than if you'd had a regular yoghurt, because you think, "It's ok, it's low-fat." But of course, you've actually eaten more calories, or sugars say, than if you'd just eaten one full-fat yoghurt. I guess that ones depends on your own self-control though. I thought it was interesting though.

Personally if my overall fat% in diet goes too low I'm much more likely to be ravenous and eat more.

So I balance them out. I do use 2% milk but most other things I eat the fatty version ... and then balance it with something like vegetables until the fat% is where I want it

i eat some things fat free simply b/c i prefer the taste
fat free milk ( can't stomach full fat yuck)
fat free sour cream ( it was the 1st i ever tried, and when i tried full fat yuck)
fat free chocolate pudding (not as sweet as full fat, though other flavors i do eat the reg version)
fat free mayo
light butter (half the cals)

everything else is full fat version, just a lil less of it