Hi T.,
Fortunately, I have 2 very hungry boys that will eat virtually anything I put in front of them. However, this hasn't always been the case!
What I have learned, is it is all in the presentation! Perhaps take them shopping with you to pick out a new set of their own silverware - mine chose Thomas the Train and Spiderman. I also let them pick out their own little plates. Believe it or not, it really doesn't matter what I put on their plate...as long as they get to pick their plate and utinsels for that meal!
I know you have already tried dips and such, but I always give my boys a choice. 'Would you like to dip your broccoli in ranch, or sour cream?' So that way then automatically knew they had to eat their vegetables, but they were able to pick what they ate them with.
Also, it helped using other names for the veggies. We pretend we are dinosaurs eating trees when eating broccoli. We are giants eating little heads of lettuce when eating brussel sprouts, etc. Sounds goofy, but they are 2 and 4...and still buy in to it!
I know this isn't much...but they are things that worked for us!
Good luck!
S.