The Ubuntu app developer project is working real good. The result can be seen in Software Center as a lot of great paid and free applications have landed and are being download every now and then. For February 2012, the following applications were among the most widely download.
Top 10 Paid Apps
1. Oil Rush
Oil Rush is a real-time naval strategy game based on group control. It combines the strategic challenge of a classical RTS with the sheer fun of Tower Defence. Fight the naval war between furious armies across the boundless waters of the post-apocalyptic world.
2. Fluendo DVD Player
Fluendo DVD Player is a software application specially designed to reproduce DVD on Linux/Unix platforms, which provides end users with high quality standards.