Labour's Annette King came in third with almost 11 per cent of the vote.
The Minister for Canterbury Earthquake Recovery Gerry Brownlee was considered the most likely to be in need of performance enhancers in the bedroom, while Mr Key was considered to be the most likely to be spotted with a sex toy in his back pocket.
TV3's Samantha Hayes was voted the country's sexiest female media personality, with 22 per cent, ahead of Seven Sharp host Ali Mau, with 19 per cent and Toni Street on 11 per cent.
New entrant this year for sexiest male media personality was TVNZ journalist Jack Tame, followed by Seven Sharp's Jesse Mulligan and veteran broadcaster John Campbell.
All Black Dan Carter and former Black Sticks wife Honor once again were voted the hottest couple, with 43 per cent backing.
Mau and her partner Karleen Edmonds came in second with 25 per cent of the vote.
The survey also looked at how New Zealanders intended to spice things up this Valentine's Day, with 83 per cent of respondents saying they expected to stay in with their partner.
Other survey highlights include:
* 71 per cent of people would prefer to receive an "exciting" Valentine's Day gift, rather than the traditional flowers, chocolates or dinner out;
* Vibe rings are the most requested sex toy (27.6 per cent), followed by vibrators (23.7 per cent) and condoms (12.2 per cent);
* Just over 80 per cent said they used sexual enhancements in the bedroom
* Nearly a third admitted to having had sex in the workplace