1. Atkins Diet (minimal carbs, no starch, high meat protein)

It gets a lot of sneers from people but it works. The downside is that it is hard to maintain. One of the benefits is of course quick weight loss making it beneficial for obese individuals and it also has the added benefit of quickly reducing cholesterol numbers although those will steady over time and if people abuse the diet they can actually regain the cholesterol problems.

2. Vegetarian (mostly fruits/vegetables, sometimes dairy and eggs)

Vegetarianism is a lifestyle more than a good nutritional plan. I don't have a problem with anybody being a vegetarian but it is a fact that many people don't really do it right. Finding some of the needed proteins your body can't make can be difficult but not impossible. To be a vegetarian and do it correctly takes a lot of planning. The apparent benefits seem to be less heart disease and other circulatory problems that can be associated with too much meat in the diet. Again, the downer is the diet is useless for anyone who wants to be muscular and strong. The muscles need proteins and the biggest bulk source for repair is from meat.

3. Vegan (absolutely no animal products)

Absolute horseshit. This is not a diet, it is starvation.

4. Mediterranean Diet (high plant consumption, fruit desserts, olive oil for fat,cheese and yogurt,white meat, eggs, low red meat, wine)

This one has the added benefit of no red meat (fatty beef) and a lot of fish and lamb. The breads when cooked like they are in the Mediterranean are far healthier than white flour based breads found in most of the west. Yogurt is very good for the gut and the diet apparently has very good vascular benefits. Of course the diet can be overdone like any diet and the person can eat too much oil and bread can be bad for everyone.

5. Paleolithic Diet (no potatoes, grains, dairy or beans, encouraged lean meat consumption, most plants, mostly water/tea as beverage)

I don't know much about this diet although I have heard of it. It is supposed to be based on a pre-agricultural diet? It kind of sounds like the Atkins but with the veggies added back in in whatever amount one wants.

6. Raw Food Diet (mostly like Paleolithic diet, but NO COOKING ALLOWED)

Sounds like a gimmick. I mean seriously, do people think our ancestors didn't cook stuff? Weird.

I'm sure I'm missing some, but these are some of the more common/more noisy diets out there. They're at least the only ones I care to ask your opinion on at the moment

The glycemic stuff is pretty good fr general guidelines on how quick and how fast stuff digests. It is important to try and keep one's blood sugar levels steady rather than spiking and dipping. I think the best book I've read on it is called the Glucose Revolution.

My personal opinion, is that all of them except the Raw Food Diet have their merits and for the most part are all based on reasonable nutrition. I just read some articles on the Paleolithic Diet and of these, I think it would be the one I followed. I just like potatoes too much. And feta. And Ice cream. But besides that, I really good do it. The bean thing sounds out-of-the-blue, but if you research the thought behind it, it does make sense.

I think individuals are different and there isn't any one diet that will fit all. I do particularly well on high protein low carb diets, my body just seems to react best to it but I know other people who have tried Atkins and felt so horrible they had to stop.
Another one you might look into is the blood type diet although some of the claims are questionable. Still when I saw the foods listed for my blood type I was surprised because they are the ones I have always digested well and the forbidden foods were ones I've always disliked since I was a kid.