While I do eat meat substitutes on occasion, dairy subs tend to freak me out (besides soy milk). They don't usually taste good, they're expensive, and they're overprocessed. The only faux cheeses, sauces and such that I eat are usually homemade.
Instead of substitutes, I prefer alternatives - foods that fill the role of dairy foods without being dairy.
Why use cheese and sour creme on Mexican food when there is guacamole to be had? Guac is so creamy, and it takes the edge off the spice. I put it on enchiladas, tacos, nachos, heck, I even do guacamole fries instead of cheese fries sometimes.
I was a huge ice cream fiend, but now I prefer sorbet. If you're craving something creamy, try peach or mango sorbet; they aren't as tart as lemon or berry.
Vegenaise kind of freaks me out. I use mustard on sandwiches. There's a zillion varieties, spicy, melloy, creamy, grainy. Find one you like, and you'll never miss mayo.
I used to LOVE grilled cheese sandwiches. Although I loved the gooey cheese, I found that when I was craving a grilled cheese, I was really craving a greasy, fried sandwich, not necessarily the cheese. So I do grilled peanut butter now. It tastes awesome. Don't grill too long, though, or the pb dries out.
I also found that after not eating cheese for awhile, roasted red pepper hummus tasted cheesy to me. But I think that's just in my head, my partner thinks I'm weird.
Anyone have any other ideas?