Bring about 3-4" of water to boil in a 3-qt. sauce pan. Shuck corn and add it to the boiling water. Reduce heat to a simmer and cook corn for 5 minutes with the cover on.
Remove corn from the water and allow it to cool while you prepare the rest of the salad.
Slice tomatoes about 1/3-1/2" thick slices and arrange on a platter or large plate.
Cut each peach into 8 wedges and arrange them over tomatoes, tucking some under so tomatoes still show through.
Thinly slice fennel and red onion and arrange them randomly between tomatoes and peaches.
Lay corn flat on a cutting board, and using a chef's knife, cut the kernels off the cob on one side. Then rotate corn and cut again, continuing all the way around the cob.
Tuck the segments of corn kernels into the salad.
Add fresh basil leaves and fennel fronds to the salad.
Drizzle olive oil and balsamic vinegar all over the salad.
Sprinkle salt and pepper all over the salad.
Serve immediately.