I hesitate to even recommend it because I don't want it widely known but better than any champagne I've had is:

Raventos Blanc Blanc de Blancs Xarel-lo

It's what champagne should be IMO. The gentle fizz, the flavor is perfect, it's gentle and delicious.

There's a lot of bad champagnes because the name only represents it origin and a certain production process but it's not an indication of quality.

Apart from that there are teriibly sweet champagnes too but mostly people serve brut/dry versions that tend to be on the sour side. I've had champagne that just tasted like grapejuice.

let me introduce you to Prosecco or Lambrusco.

It’s only bitter if you get a dry type. Get a sweet champagne.

I'll echo something others have said in reaction to other drinks, but it sounds like you've not had good champagne then.