E.
I purchased a boy's urinal "Peter Potty" for my youngest (2). My older (3) was EZ, but my youngest son doesn't like to be "told" so I gave him a choice. This solved our problem. He is very stubborn and this helped us get over his fits of defiance.
Best advice: Don't use pull-ups. Use training pants. The uncomfortable feeling helps the child associate potty in the pants to potty in the toilet.
You might try a "break" w/ your son and try again in another week or 2. That's what I did w/ both my boys. We watched videos and read books, let him go w/ Daddy and me to potty in the meantime til we were ready to start again. I use a time schedule (q 15 min)the first day and then lengthen the times in between to where eventually he tells me. It also helps to do this when you have a couple days w/o interruptions so you can be home.
My boys didn't respond to incentives, they responded to the "BIG BOY" praises big time. It also helps to plan a quick outing (store/park) and to get him to use potty before trip, while out (very exciting to my boys) and of course when we get home. This really helped my boys understand to use the potty independently.
NOte: I still use diapers at nite for my youngest since it's been a month and my oldest uses pull-ups at nite and is staying dry!
Good luck to you and yours. Stay patient and remember to praise, praise, praise. Especially while he helps clean up his accidents...