Dubai is the smartest place to invest right now, for the economy is still booming and there are no taxes! The most lucrative is to buy in the form of buy off plan property DIRECT (better prices before secondary market for better return) but you have to TRUST the developer in delivering quality, delivering on time and delivering what they promised! The developer must be registered and have an escrow account, as this system secures that the funds will only be used for what they were intended for.
Location is the the key thing to consider on top of your list! The investors who missed out on Palm Jumeirah now have a second chance with Palm Jebel Ali. There are many projects launched on the Crescent areas since Cityscape.