"Fireflies" by Owl City and "Blame It" by Jamie Foxx. Weird Al included these two in one of his polka mixes and they work so well together!

birdhouse in your soul by tmbg into butterfly by smile.dk (that song that goes AY AY AY IM YOUR LITTLE BUTTERFLY!!!!!).... my friend found it nd i am flabbergasted how the HELL do they go into eachother so well.

also i love albums where each song goes into the next one... like pretty much every lemon demon album has that nd i love it!!!!!

https://youtu.be/Ki3wYxWlohk this into https://youtu.be/bv0_KXEwNUw they dont transition that well but i wish they would

oh I have tons.

1. Kraftwerk - Numbers (3-D) into Computer World (3-D). Uno two zwei four, uno two zwei four, 38294738372728373, one two three four, COMPUTERWORLD!!!
2. C418 - Kompass (with Disasterpeace) into 185 (with Baiyon). So smooth I didn't even realize they were separate songs at first, and they were originally made for two different albums!
3. Orbital - Lush 3 into Impact, and Impact into Remind. Again, so smooth they could be one song, and they should never be played separately.
4. Ryoji Ikeda - ultratronics 00 into ultratronics 01. Robot introduces itself with its specifications, then immediately glitches out.
5. Every. Single. Transition. On Jean-Michel Jarre's Equinoxe. It's like one long symphony, but all the movements have their own identity.