I adore rhubarb, and the amount of rhubarb I use is pretty good evidence of this. It's in season all summer long and pairs well with strawberries raspberries, lemon or simply sugar. So a couple of the tarts I've made lately have rhubarb in them. The bottom one is simply rhubarb + strawberry + kirsch and some whipped cream.
The top one is a vanilla tart with rhubarb infused with lemon zest and a few left over raspberries. A really tart tart.