If you're cooking for meat-eaters as well (been there, done that!), it can help to cook or plan essentially the same meal, but swap out the protein. So if everyone else is having meatloaf, broccoli, and sweet potatoes, you'd just swap out the meatloaf with veggie non-meatloaf. (There are a zillion recipes on the web for this--I like ones with nuts and beans--and the Amy's frozen ones are decent, too.) There are frozen veggie burgers that are fine, but it helps to avoid the ones with a lot of soy and fake meat stuff in them.
Also, do it yourself meals, where everyone makes their own tacos, burritos, or pizzas, are great, especially because you can use whole-grain/higher-fiber tortillas and crusts. Taco salads are also excellent.
I can't eat a lot of carbs but have to get a good bit of protein for health reasons, and when I'm in a hurry, the frozen black bean burgers seem to be the best option for me. I also make my own, using Mark Bittman's basic bean burger recipe, and freeze them. I eat tofu once or twice a week, usually in miso soup. I also like steamed or roasted veggies with hummus, as well as veggie fritatatas and omelets.
This is sort of random: My kids are going crazy for this black bean pasta that I found at Costco. It's high in protein and low in net carbs, and it's AWESOME with peanut sauce and whatever veg happens to be around.
I agree with the PP who said that ultimately, he needs to take responsibility for his own diet, but there are ways to make it a positive experience. Also, as another PP mentioned, the Moosewood cookbooks are awesome. (If you can, try to find the older editions:
http://www.amazon.com/The-Moosewood-Cookbook-Restaurant-published/dp/B008TCJXOK/ref=pd_cp_b_0).