My definition of "forgiving" is good arrow flight with less than perfect form (grip, release, etc).
I would say a longbow with a forward grip would be the most forgiving design. The thicker limbs add stability and a forward handle reduces the affects of torque.
I have shot several different models of this style bow and had good results with them.
For me personally, a hybrid longbow with a contoured grip (not recurve riser w/longbow limbs) suits me the best. I have a Thunderhorn 62" longbow that I can get real sloppy with and still have great arrow flight. My buddy has a Big Jim Thunderchild and shoots it better than anything else. Both of these bows are examples of what I consider a forgiving bow design.