Oh god, there are so many things wrong with this show. For one, the same thing happens in every episode. Yeah, Phineas and Ferb have a different idea, but half of the words spoken are the same in EVERY episode. I understand that most cartoons have repetitive plotlines, but this is probably the most repetitive cartoon I've ever seen. Also, the whole Perry vs Doof storyline is a blatant, and really bad, ripoff of one of my all-time favorite shows, Kim Possible. As for the show's main plot, here's what Phineas and Ferb is all about:
Phineas and Ferb get bored. Then Phineas gets an inspiration to do something and says "Ferb, I know what we're gonna do today", followed by "Hey, where's Perry?" Then Perry goes through some kind of hole or opening (Because Major Monogram seems to have the entire world connected to Perry's little secret base), gets his instructions and goes off to fight Dr. Doofenshmirtz. Meanwhile, Phineas' & Ferb's mom leaves to run an errand, and leaves Candace in charge, who tries really, really hard to bust Phineas and Ferb. The two kids order parts for their large creations (I still have no idea how they can pay for them). The delivery guy asks them "Aren't you a little young to-", followed by Phineas answering "Yes. Yes we are". Then cue Isabella, "Hi Phineas. Whatcha dooin'?" Meanwhile Perry gets to Doofenshmirtz Evil but gets immediately captured (You'd think he'd have figured out the pattern after doing it so many times). Then Doof tells a backstory, followed by "Behold! The --inator! (Seriously, can't he think of something else?). The kids get their contraption together, cue the pointless musical number thats always gonna be awful. Candace sees it and rushes to get her mom. Perry then breaks out of his trap and easily beats Doof, he screams "Curse you, Perry the Platypuuus!!", and his invention destroys P&Fs invention before their mom can see it, so Candace is left looking a little crazy to her. Finally, Perry shows up and Phineas goes "Oh, there you are, The End. There you go. That's your whole show.
For another thing, most of the characters of this show are not very likable. Especially Candace, who's whole life, apart from trying to bust her brothers, revolves around a boy named Jeremy. And why does she care so much about busting them anyway? Is she actually younger than her brothers but just had a growth spurt early? Or is she just really that immature and crazy? She's especially despicable when she tries to bust Phineas and Ferb when they try to help her out, like in Moon Farm or even on Phineas' birthday. Seriously, what a bitch! Also, Doofenshmirtz completely fails as a villain, not to mention annoying with all his ramblings. I'll admit though that Phineas and Ferb themselves are pretty nice kids, and are the best characters in the show. Also, there's not anything really inappropriate in Phineas and Ferb, so it's a good show for little kids I guess.
In closing, Phineas and Ferb isn't good. It's plot is annoyingly repetitive, and it's B-plot is trying too hard to be like a much better Disney cartoon. The fans can hate me all they want, but It's just my opinion. Phineas and Ferb is one of the most overrated cartoons ever made and unless your a little kid, its not worth watching.