"I Can't Hear You"

Branden has had 2 major ear infections for the past 2 weeks. He's seen the doctor twice and is on his second round of antibiotics. I am running out of creativity and patience! He will NOT take his medicine. We have tried juice, food, chocolate milk, using a dropper and pretending its Tylenol (which he LOVES)... and AH! its driving me nuts because we can only use each method once before he figures it out and refuses to do it again. We have wasted so many doses and I'm afraid he's not getting as much as he needs to kill the infection.

Recently, he has been showing signs of defiance.. not in a rude way (its hilarious, actually) but it still makes me sad that we don't all stay sweet and obedient forever! I thought I'd get a good 5 years out of him so its depressing to think it lasted less than 2 years :(

Example #1: If I tell Branden its time to change his diaper, he runs in the other direction. This is probably the most typical way kids defy you at a young age.
No biggie.

#2: When I say its time to take a bath or get his PJs on, he immediately lays down, closes his eyes and says "Ashoo, ashoo" like he's sleeping. Zzzzzzz....
Brilliant!

but the most shocking of all is the most recent example...

#3: Last night I was beyond my level of patience so Jeff took over and tried to have a serious talk with Branden about the importance of taking his medicine. Branden slapped his hands over his ears, squeezed his eyes shut and started singing!!!!!

WHERE THE HECK DID HE LEARN THAT?!?!?

I am nervous for our future.

Any ideas?
How do I get him to take his medicine without loading it with sugar, or so he doesn't throw it up?
What do you do when your kids want to be independent and/or defiant?
How do you teach them a behavior is wrong when you are trying your hardest not to laugh or think about beating them (not really) because you are in complete shock that this little body and brain is WAY too smart for anyone's good???