I second the RX100 series. As a step up, there is RX1 with a full frame and fixed lens. And HX99 the other way with a smaller sensor, but goes all the way up to

I second the RX100 series. As a step up, there is RX1 with a full frame and fixed lens. And HX99 the other way with a smaller sensor, but goes all the way up to 720mm.