Panjim and the night life!!
Panjim is worth spending the full day. During the day time one can visit the UNESCO heritage site (Basilica of Bom Jesus) and Arachelogical Museum of Goa. The ride to these sites is memorable, no matter the mode of commute.
Nightlife in Panjim is fun. Various floating casinos and ship rides are a must. The cheapest ship ride worth 500 bucks was value for money!!