Colaba causeway.. beside gateway of India, take a ferry from there to elephanta caves, then marine drive, girgaon chowpatty. take a ride on bandra worli sea link, sunset at Bandra bandstand beside SRK's house. u can also go to borivli beside essel world for the vipassana pagoda, amazing place .
Marine drive.
Gateway of India. Must Visit. Colaba Causeway. Juhu Beach. Must Visit. Siddhivinayak Temple. Haji Ali Dargah. Must Visit. Elephanta caves. Must Visit. Girgaum Chowpatty.
Bombay port trust garden
gateway of India
causeway
nariman point hanging gardens
sewri mangroves
nehru planetarium
girgaum Chowpatty
girgaum bandstand
walkeshwar viewing point
worli seaface
borivali national park
In particular Mumbai for view of sea,
Juhu beach
Necklace point
Girgoan chaupati
if u are a shopoholic person
visit fashion street
lime road
dadar market
if looking a bit beyond mumbai,
try konkan...
raigad, alibag, Ratnagiri etc
Global Vipassana Pagoda , Marine Drive , Juhu Beach , Haji Ali , Gateway Of India , Elephanta Island , Borivali National Park , Worli Seaface , Bandstand , Chowpatty..
Bandra Fort.
Elephanta Caves, Gate Way of India and Mumbai Fort Area including CST Station. Marine Drive, Malabar Hill and Gardens, Siddhi Vinayak Temple, Borivali National Park and Kanheri Caves.
To see victorian time Mumbai and posh Mumbai, go to churchgate station. Go to CST station, colaba causeway, marine drive . And for Bollywood darshan, go to goregaon east, go to film city. For beaches, go to juhu beach, although it's a clean beach but food is good there. You may see some celebrities there too. But for much beautiful beach experience, go to Gorai beach. it's a typical Marathi locality beach. you will get a Goan type feel also. it's a clean and secluded beach. For shopping , do visit Linkroad , Alko road, crowford market for shopping.