Best meat replacements for a vegetarian/vegan?
Pardon my rampant vegerianism, but the trick is not to substitue meat at all.

I generally get my nutrition from other sources, without using meat substitutes at all.
Unless I really feel like a certain recipe that I used to like back in my meat-eating days.

Use beans, lentils and whole grains for protein.
Use nuts, seeds and avocadoes (or any other fatty fruits and vegetables) for B-vitamins.
Use beans (again) and leafy greens for iron and calcium.

So, it turns out my answer is a bit Zen.  Sorry.