Hi, ajc! I love to cook too, and I'm finding I really have to stretch my imagination to keep meals both healthy and exciting.
Do you like Indian food? I find Indian dishes a great inspiration when cooking vegetables. Same goes for many Chinese and Japanese dishes too. Borrowing dishes from cuisines and cultures that have a history of eating vegetable-rich meals has had good results for me.
Some recipes "lighten up" more easily than others. For example, I'm a huge fan of New Orleans-style red beans and rice, but had to change the way I cooked it a bit. My new version contains a much bigger proportion of beans to sausage (the andouille is now just a flavoring, not a major ingredient), has additional celery, green peppers, and onion to make up for any flavor lost from the sausage, and is served over a lot less rice.
One suggestion that I've read and loved here at 3FC is to turn many of my favorite sandwiches into lettuce "wraps" instead. Chicken salad tastes as good (or better!) when daubed into a butter lettuce leaf than it would on boring white bread. A BLT doesn't actually need bread to be a BLT. (This doesn't work with all sandwiches, though--a PB&J on lettuce would be pretty vile.
As for outright substitutions, some folks love 'em and find them satisfying, but I am generally not a fan. I'd rather eat nothing containing cheese, cream, or butter at all than use low-fat or artificial versions of these things. There's just no way to make fettucine alfredo fit easily into a healthy eating plan, so why make an unsatisfying fake version that will only leave me craving the real thing? That's my take on it, at least. Instead I'd rather look at recipes that start off fairly light to begin with.