Since I lived in Kuala Lumpur. Why don't I tell you guys about my places? Firstly, KL is the Capital city of Malaysia. It is where the entertainment starts all day !!!
For me, I suggest you guys go Dataran Merdeka which aka Merdeka Square. It was here the Union Flag was lowered and the Malayan flag hoisted for the first time at midnight (time: 12:00 AM) on 31 August 1957. Since then, Merdeka Square has been the usual venue for the annual Merdeka Parade (National Day Parade). But not to forget, at night this was probably the busiest place to visit but trust me you'll never regret!
Next stop Changkat Bukit Bintang. I believe most people who have been in Kuala Lumpur know this place. It's a must to go here during the visit. All the clubs, pubs and bar are here and many people go here to have fun. Not to forget, pretty girls and handsome guys are there too if you want to find one. 
You'll find clubs such Movida, Havana, Zion, Mango, Beach Club and many more!!!!
Stay tuned for the updated story Part 2!