Unfortunately, I didn't see the original 3 Muppet movies in theaters (not quite old enough)- but I do recall going to see all the Muppet movies in theaters, from "The Muppet Christmas Carol" forward. As to "Muppets From Space"- I too noticed that there weren't original Muppet songs there, but mainly I just enjoyed going to the movies and watching it. It was fun seeing some of my favorite "Muppets Tonight" characters mixed in with the classic Muppets- and seeing them all in the boarding house together. And the movie had both "Brickhouse" by The Commodores and "Celebration" by Kool & The Gang in it, so I was pretty happy with those for music choices- two favorite songs for me.
So yeah- overall, I loved this movie, along with all the other Muppet movies!
And "The Muppets Take Manhattan" is just classic- love it! It was one of the last Muppet movies I saw though- for some reason, I could never seem to find that on video until it was rereleased to VHS in 1999.
"The Muppet Movie" is the ultimate classic- I'm pretty sure I've probably seen that one the most... I love watching it every time.
And for the record, though I don't like some of the "edgy" parts, I generally enjoy "The Muppets' Wizard of Oz" pretty well. I particularly like some of the music from it.