I would suggest fun disposable type stuff, Bubble bath and bath tub toys and crayons add some cool character towels to up the expense.
New bed sheets and jammies with character on it.
At that age I would go with nice wooden Ravensburger puzzles.
Maybe for next year, ask uncle and grandparents to go in on one really really big thing.
Not picking on you queen of the castle But, i'm wondering something. At this time of year, knowing people will be asking me for gift suggestions for the kids and myself, i really limit what I am out buying. My dd needs new pj's and I could have bought her them at thanksgiving, but instead i asked sil to get her a new pair for christmas, don't get me wrong it wasn't that the jammies were so snug she couldn't breath or so short that they were up to her knees, but they were just starting to be outgrown. I am a frugal person and i could have gotten the jammies very cheaply, possibly even used, but knowing I didn't want more toys in my house ( gifts from sil) jammies are what I suggested to Sil. see what i'm getting at? Especially with young kids like yours, I would think there would be things you could plan ahead for others to possibly get. maybe your family doesn't follow your suggestions though, i don't know.
ok and now i am picking on all you aunts. What is the deal with insisiting on seeing their eyes light up and giving them the most awesome gift ever??. There have been some posts recently with the grandparents feeling entitled to play Santa and out shine the parents. I get that you don't want to just get them underwear but it almost sounded like you were trying to compete with Santa AND mom and dad. Am i misunderstanding?
anyhow, it seems like you've gotten some great suggestions. I hope your holidays are merry and bright! i'm off to have some eggnog and play board games with my babies.