Buy great spices and seasonings! I'm a big Penzey's fan - they have great blends and rubs so I can grill or bake chicken 3 nights a week and not feel like I'm eating the same thing over and over again.
I also try to "prepare" two meals at a time. Tonight we're having roast pork so I bought a big one. We'll eat about 1/3 for dinner and I'll throw the rest in the crock pot with a can of ginger ale and some onions and a little seasoning. When it's really tender I dump it, throw it back into the crock pot and shred it, then add a bottle of spicy BBQ sauce. VIOLA! Easy pulled pork that freezes really well in portion controlled freezer bags. (just be careful to use BBQ sause with low sugar content or it may burn)