Like you, I did not want Easter to become a 'second Christmas' with regard to getting 'gifts'...
My mother used to give me a basket filled with mostly inexpensive items, and she would hide the basket on Easter morning and I had to hunt for where the Easter Bunny hid it. I LOVED THAT. And I remember enjoying receiving a basket for Easter, and did not expect gifts like I got on Christmas. I want the same for my son, who is now 3.
Like most of the others here, I plan to do a basket with minimal candy... I got several items in the dollar section at Target - they have some great things. My son likes note pads and stickers, bubbles, stampers, crafty stuff, little bags of fruties, teddy grahams, play-doh, sunglasses, books, etc.
Another idea is to put in a few items that either you could use in the household in general, like cartoon band-aids (my son loves them), or character bath soap or shampoo, etc. Or you could include a couple things your son will need for the upcoming spring or summer like maybe swim trunks, or a couple summer t-shirts, etc... This way, you are spending money on things you might need at some point anyhow!
Also, you can be creative about what you use for your basket. My mom used the same one for me throughout my childhood, and that is certainly an option, but I recently found at Wal-Mart, this adorable child's gardening bucket that is the pull-cart type... it has a high back on one side with a handle, and wheels for pulling. I thought that would be a great toy for summer, with my son always hauling around his sand toys, or gardening tools, etc., and then it can be brought in for the winter to cart around his toys inside... and it was only $10 - this is going to be our basket this year. A laundry basket is another multi-purpose basket solution!
Best wishes!