No doubt Manali. For the cool weathers, cold nights, mist and fog touching you, lush greenery around Manali is an ideal summer spot. Goa is no doubt a lovely spot but scorching heat prevails all through summer. Ideal time to visit Goa is from July.
Hi...I am from Goa ..so I suggest you visit Manali now. Goa is best to be visited in winters for its lovely beaches and in Rainy season for people who love hiking and frolicking in the water falls in deep forests of Goa.