Good Feeling, Feeling Good, Feels Good
expression, い adjective
When you have a "feeling" (気持ち) that is いい (that means "good" by the way), you have a good feeling.
きもちいい
The reading comes from the vocab word 気持ち, so if you know that (or the vocab words 気 and 持ち) you should be A-okay on this one. Maybe even feeling good about it?
このブランケット、気持ちいい。
This blanket feels really good.
家がきれいだと気持ちいいよね！
Doesn't it feel good to have a clean house?
マッサージ中、気持ち良すぎてイビキをかいてたみたい。
It looks like I felt so comfortable that I was snoring during the massage.