Electric-type Pokemon have always been pretty popular, especially in the early days of Kanto and Johto.
The likes of Pikachu and Zapdos set the standard extremely high for Electric-type Pokemon introduced throughout the Generations. Calling the first iteration of Electric-types popular is an understatement.
As fans journeyed to the Johto region, those original Pokemon were still available. New ones were then discovered that trainers immediately took a liking to.
Note: This article is subjective and reflects the opinion of the writer.
3 most popular Electric Pokemon from Johto
#3 - Ampharos
In the games and with Ash in the anime, an Ampharos was under the weather and needed some medicine. Once it recovered, it illuminated the lighthouse in Olivine City. That was the debut of this Pokemon, giving it a bit of sympathy from fans.
Those that latched onto its popularity were quick to find out its usefulness. Ampharos has solid HP and a wonderful base Special Attack stat.
#2 - Raikou
Pokemon fans love the idea of Legendary trios. From the birds of Kanto to the forces of nature, Legendary trios are a huge part of Pokemon. Generation II and Johto saw the second instances of this with the beast trio.
All three of the beasts are extremely popular. The Electric-type, Raikou, may be the least popular out of the three, but it is certainly above the other Electric-type Pokemon introduced in Johto. The strength and lore of Raikou is amazing.
#1 - Pichu
If there was anything that could rival the Electric-types from Kanto, it was going to be an addition to one of its evolutionary families, and that's where Pichu comes from.
Pikachu and Raichu are considered some of the cutest Pokemon around. While Baby Pokemon are a bit divisive, it is safe to say that fans of the series absolutely love adorable creatures that can be turned into merchandise. Pichu is exactly that and is extremely popular because of its cuteness and ties to Pikachu.