How about a Mr. Goodbar? It speaks for itself.  Or Milky Way because they're out of this world? Or Twix-betwix(t) you and me, we think you're great! OR, one of those Hershey dark chocolate bars, the ones that say Special.  Or you can put some Nestle Treasures candy and a couple pieces of fudge in a Ziploc baggy and put in a note that read: Just wanted you to know how much we "treasure" you and we're not "fudge'in".  (Idea by Linda Baker).

We just got a new bishop about 2 months ago, so we will be doing something on Father's day about the father of our ward. I think we will have him come in, and sing for him, and our ward's bishop always has a photo of the Young Men/Young Women and the Primary in his office. They are usually taken when he is made bishop, and then every couple of years, and the Bishops take them when they are released. So, we took a group photo, and we will have the kids sign the mat, and then frame it and give it to him for his office. The children like to see themselves and their signatures both when they are still in Primary, and when they move up to Young Men/Young Women.  In the past our ward has also done a flower garden theme and had each child write on a flower that was taped to a wooden skewer and stuck in florist foam in a clay pot for his window sill, I have also seen the "heart attack" idea used on the Bishop's door during sharing time. (Idea by Jamie)
In one of our wards we made flowers heads with petals, all one piece. We drew in the petals and the centers. In the center the children wrote their names and then on each petal (I think there were 4) we had them write things they would do to keep the commandments, honor their parents, how they could act in church etc.... We then glued the flowers on tall straws and put them into a large vase. We presented it to the Bishop on Father's Day. He had it on the podium the next week and then kept them on his desk for the remainder of the year and into tithing settlement and thanked the children for them individually when they came into tithing settlement. It was a fun thing. (Idea by Joann Mortenson)

"Ahead of time I get a pair of the Bishop's shoes and collect small inexpensive items with a thought for each to "fill his shoes"   Some Ideas:

Kleenex- "He shed tears for us when we make a wrong choice." 
Light Bulb - "He has many "Bright Ideas" to help our ward." 
Rubber Band "He has to have a flexible schedule." 
Treat- "He is sweet to every child." 
Small Water bottle- "He helps us prepare for Baptism." 
Toothbrush- "He has a big smile for everyone." 
Ruler- "He measures our spiritual growth at each interview." 
Eraser- "He helps us erase our sins through repentance." 

Before he comes into Primary I taught the children the song "He's Our Bishop".   I explained how the bishops job is hard and he has "pretty big shoes to fill," but today we're going to try and fill them for him.  We sang to him and presented him with the "gifts" and thoughts."  (Idea by Jan Larson)