In general, a bug-type isn't hard to beat. It's one of the most resisted types of Pokemon in the games. For that reason, Bug -types largely get overlooked in favor of something better. There are currently 84 Bug-type Pokemon across all generations. Some of them will be favored even when the rest aren't.
5 most popular Bug Pokemon of all time
#5 - Pinsir
Since Generation I, Pinsir has been a defining Pokemon type that looks great and has stood the test of time. This bi-pedal Bug-type has an iconic set of pinsirs that give the Pokemon its name.
What made Pinsir even more popular was the Mega Evolution it received, which looks awesome and has wings. Though the base Pokemon doesn't have any other forms, a Pinsirite held by a Pinsir allows it to evolve.
#4 - Heracross
Like Pinsir, Heracross is another fairly iconic Bug-type based on a bipedal design for the Pokemon. It also shares other characteristics like it has no other forms aside from a mega evolution.
What sets the blue beetle apart is the mix of being a Fighting and Bug-type. As a generation II follow up to Pinsir, it offered even more as a great Bug-type pick. Whether as part of a collection or in battles.
#3 - Genesect
Perhaps the most intimidating Bug-type, Genesect is the only Mythical on the list and the only Bug Mythical in Pokemon. It's a dual-type of Bug and Steel that resulted from an experimentation by Team Plasma in Generation V.
Genesect is also a formidable pick that separates this Pokemon from many other Bug-type Pokemon games in battles. The lab-made Pokemon is certainly a popular one.
#2 - Volcarona
Another Bug-type from Generation V, Volcarona, evolves larvesta at level 59, which is a very high point. Though a long grind, players always consider it worth it because of the strength and popularity of the Pokemon.
It's a Bug and Fire-type, which gives it some advantages over many other Bug types available in the games.
#1 - Scizor
Scyther was already a fan favorite Bug-type Pokemon, and in Generation II, his upgrade stole the show. Scizor is a Bug and Steel dual type with a fantastic and intimidating red design.
Fans love Scizor for the design alone, and its strength in battles only means it's here to stay.