There's this Italian guy with a youtube channel called Myguid0. He's made a LOT of pretty realistic original paper airplane designs, none of which require cutting or gluing to make. He gives you step by step tutorials on how to fold each of them. They're kinda meticulous to make, though, since you'll need a ruler and a pencil to measure out and mark the locations of folds, but the final products are definitely worth the effort IMO. His Su-47 design is my favorite, by far.

They all require A4 sheets of paper to make, though, so I just trimmed off a sheet of letter paper to A4 proportions and scaled down each indicated measurement proportionally to make each plane.

Unfortunately, his last video was made two years ago and he hasn't come back and uploaded to his channel since, which is a bit of a bummer since I would've loved to have seen more of his designs if he made them. Nonetheless, I highly recommend checking out his channel and his videos for some cool paper plane tutorials.