I loved this TV show "Ultra Seven"(1967-68) when i was a kid, I saw it before knowing Ultraman was the original, but for me Ultra Seven is much better, It was cool, he transformed by wearing a pair of "sunglasses", and he didn't have the time limit that Ultraman had. Unlike Ultraman, Ultraseven can make himself, giant, normal, or miniature in size. And he had a very cool weapon, a very sharp "boomerang-blade" on top of his helmet.
And the stories were very nice written for a show mostly done for kids (writters: do not under estimate kids) and "Gozilla" fans. Some of the shows were very impressive for me,I had to turned off the TV when he made himself miniature and entered in the nose and lungs of a girl to save her life, well I was a kid. The show was filled with good drama, acting, lot of monsters, space gadgets, and cool monster-kicking action. I think they made a remake of Ultra Seven in the late 70's but I'm no sure, I just say it because the second time I saw the show,the stories where the same but it looked different than I remembered (maybe it just the memory of a 6 year old to blame), it does not matter any way.
I think Ultra Seven and Ultraman inspired the Power-Ranger series (not my favorite show), but if you like them do not miss the originals, they are fun to watch.