Scania 113 rulez!!

The engine is one of a kind. it has such strong urge, yet remains earily quiet til the rpms hit a high. . . . . Just revel in its SILENT ACCELERATION. Initial move-off from stationary is close to silent, yet acceleration is so strong!! This must be the Lexus of Buses. Its my fav cuz it has loads of character.
Merc Hispano 0405 comes in a close 2nd. Super torquey diesel, shiok engine note when floored! esp at highway speeds. The power comes on so smoothly and strongly. Plus, it just sounds so damned powerful!! Although roll is excessive, it has the most comfortable ride of all. My favourite bus for 40winks. 0405 is second cuz its the most competent bus in S'pore, though not the most interesting.
3rd would be Dennis Lance (new one, not the Malaysian ones). This model is used to shuttle pple working in Tekong to and from White Sands. Twin-turbocharged Cummins really stirs me up whenever the driver floors to overtake slower cars along Loyang Ave. Always eager to kick down at the slightest prod of the gas pedal. First the downshift and the twin-turbos howl with rising intensity as they awaken, turbines spinning up wildly, torque rising relentlessly, without a sign of breathlessness. . . . then the next gear kicks in and everything starts all over again. The experience is divine.

3rd prize cuz i like its race car character!
Volvo B10M Mk II with Duple Metsec body is 4th on my list. I enjoy the growl of the engine. Its sounds hardworking and feels punchy. Gearing is abit low so it sounds like ya travelling really fast sometimes. Interesting mid-engine layout. Has the best sound of all Volvos.