Another vote for the 3rd photo. It looks like something out of a sci-fi movie, as if an alien spaceship is hovering in that bright spot. This is the first time I've seen a picture of a cluster of lightning bolts, all of them vertical, and all of them emanating from a common bright source.
Here's some critique:
1. First, these are good shots. You were in the right place at the right time.
2. I don't think fisheye is the best lens choice. I know you wanted to cover a large area because you never know where the next bolt is going to come from. However, 24mm (FF equivalent) might have been sufficient. It would have produced less barrel distortion.
3. Straighten the horizon, particularly in shots 1 and 3.
4. Because lightning is the subject and is already bright, I would suggest darkening the whole image gradually until the foreground and clouds are dimmer. Photo 1 has darker background and clouds, which adds to the visual excitement. Photos 2, 3, and 4 are overexposed.
5. The photos seems slightly blurry. Gradually apply a sharpening filter, but be careful never to over-sharpen.
6. In Photo 1 there is a little baby lightning bolt on the far right. Crop it out to focus on the main bolt.
7. Photo 2 is centered between two strikes: a very interesting "bridge" or letter-H on the left and high-altitude horizontal strikes on the right. However, the left pillar of the bridge is cut off a little above the ground. That's a shame. If both pillars were fully in view and centered in the frame, it would have been wonderful.
Finally, it's good to see people giving the P button a rest and doing some manual or Bulb exposures.