Which smartphone OS is the one most people want? That depends, according to the results of a Neilsen survey released Wednesday, on the demographic.

Current smartphone ownership is dominated by three mobile operating systems, with Apple’s (AAPL) iOS, Research in Motion’s (RIMM) BlackBerry and Google’s (GOOG) Android accounting for nearly 80% of the market.

No surprise there. The interesting results emerged when Nielsen asked would-be buyers what smartphone they most desired. Women, it turns out, tend to prefer iPhones, while Android phones have a slight edge among men and smartphone upgraders in the 35-to-54 age bracket.

Below: Nielsen’s summary of its findings.

• Among users planning to get a new smartphone, current smartphone owners showed a preference for the Apple iPhone (35 percent), while 28 percent of both smartphone and featurephone planned smartphone upgraders indicated they wanted a device with an Android operating system as their next mobile phone.
• Featurephone owners planning to get a smartphone are less likely to have made up their mind about the OS they will choose: 25 percent were “not sure” what their next desired OS might be compared to 13 percent of smartphone owners. Those over 55 were markedly less certain than younger mobile users, with 27.8 saying they weren’t sure what kind of device they wanted next, compared to 12.2 percent of those 18 to 24.
• Apple’s iPhone and devices with the Android operating system were the “most desired” among likely smartphone upgraders, with Apple showing a slight lead among those age 55+ , 18 to 24, and 25 to 34.
• Women planning to get a smartphone are more likely to want an iPhone as their next device, with slightly more males preferring Android.

You can read the full report here.

[Follow Philip Elmer-DeWitt on Twitter @philiped]