on top of the world

be / feel on top of the world {infml} (to feel extremely happy) — чувствовать себя на седьмом небе (от счастья, радости, восторга)

Example: What a great time we had that night; we were on top of the world! (GoEnglish.com)

[over the moon]
[on cloud nine]
[на седьмом небе]

feel like a million (be in the best of health or good spirits)

Example: After winning that prize I feel like a million.