What do toddler boys like to eat??

I mean really?? I cannot get D to eat anything!
OK, he will still only eat a handful of foods. The only things he will eat every time are: yogurt (but it has to be the kids kind with all the sugar and bright colors that do wonderful things to his poo), the marshmallows from Lucky Charms (do they make a cereal that has only marshmallows? 'Cause 90% of the box goes to the dogs.), and mashed potatoes (as long as they aren't real ones).

It's so frustrating! I don't know how he is even gaining any weight. Seriously, for about two days all he ate was breakfast. He may have taken a few bites of mac & cheese or a chicken nugget... but really he was just playing with his food: organizing it, throwing it, spitting it out...

I tried mixing B's baby food into his mashed potatoes. It worked the first time. But the second time he turned his nose up at it... but did eat all my mashed potatoes...

The night before last I made him 3 different things for dinner. I always give him whatever we're having and then have a back up plan for when he won't eat that. He wouldn't eat what we were having, so I made him some of those ramen noodles (which he will usually eat). Wouldn't touch them. After everyone else was done eating I started feeling awful guilty - thinking that he had to eat something... I had a kids spaghetti frozen dinner in the freezer, so I made that for him. Well, he transferred all the noodles from one compartment to the next and maybe took two bites...

I feel like I've tried to get him to eat just about everything. I'm all out of ideas. The foods he will eat sometimes are chicken nuggets, mac & cheese, stuffing, hot dogs (rarely), spaghetti-o's (rarely), rice, lasagna, cheese and refried beans.

I actually went and hunted down liquid vitamins. He wouldn't eat the few kinds of chewables I tried.

Does anyone have any ideas? What are your toddlers favorite foods?