First, new spacecraft built exclusively for deep-space (Lunar, Martian, etc.) operation. It will be based on the general shape of the Soyuz capsule. A small re-entry craft (possibly based on the Space Station escape vehicle, X-38 I think) docked to a mission module made as light as possible for maximum cargo (perhaps derived from the BA Genesis modules. Light-weight and respectable living space). It would weigh (hopefully) no more than ten tonnes, and have a methane-oxygen engine. It would launch by Falcon 9 rocket, or one of the lighter Deltas or Atlas. The Ares 1 was a complete mistake. 25 tonnes to LEO, but only for one capsule.
Alternatively, the money can be spent on Cassini II and Cassini III: Cassini-based probes for Uranus and Neptune. Or a Titan lander.