I myself was always a fan of Hitman 2. The original had more trips for failure, where in Hitman 2 there were (by design) at least 3 ways to achieve a mission. The third (or fourth) was brute force, which was always an option. Back from the days in the first Hitman (or the first No One Lives Forever, or even Thief) where being seen equals instant mission failure grew maddening after awhile. Granted, stealth was the point, but I was never fond of such rigid adherence to protocol.
And frankly, sometimes a Hitman walking into a room and hosing everyone down is more appealing on the visceral level.