Formal:
* आज आप बहुत सुंदर लग रहे हैं। (Aaj aap bahut sundar lag rahe hain.) - This is the most literal translation and is suitable for addressing someone with respect, like an elder or someone in a position of authority.
Informal:
* आज तुम बहुत हैंडसम लग रहे हो। (Aaj tum bahut handsome lag rahe ho.) - This is more casual and appropriate for friends or someone you are close to.
* आज तुम बहुत अच्छे लग रहे हो। (Aaj tum bahut achche lag rahe ho.) - This is another casual way to say it, meaning "You look very good today."
Romantic:
* आज तुम बहुत प्यारे लग रहे हो। (Aaj tum bahut pyaare lag rahe ho.) - This translates to "You look very sweet today" and can be used with a romantic partner.
It's important to choose the right phrase based on your relationship with the person you are talking to.