There are a ton of missions to cover, so I'm going to just start going through the
index of current missions alphabetically. There are eighty-five current missions listed!
First up is the Advanced Composition Explorer or
ACE.

Launched: August 25th, 1997
ACE is orbiting the L1 libration point at 1.5 million miles from the earth and it's mission is to study accelerated particles from the Sun, interstellar and galactic sources:
Study of these energetic particles contributes to our understanding of the formation and evolution of the solar system as well as the astrophysical processes involved. The Advanced Composition Explorer (ACE) spacecraft carrying six high-resolution sensors and three monitoring instruments samples low-energy particles of solar origin and high-energy galactic particles with a collecting power 10 to 1000 times greater than past experiments.
Mission Status: Last update April, 2008
ACE has been at the L1 point for over 10 years, and the spacecraft and instruments are still working very well, with the exception of the SEPICA instrument. Due to failure of the valves that control gas flow through the instrument, active control of the SEPICA proportional counter is no longer possible. At this time, we do not expect to deliver any SEPICA data beyond Feb 4 2005, unless one of the valves opens by itself, as has happened a few times in the past.
Realtime data from ACE is used to help with the forecasting and prediction of solar storms.
By conserving fuel, it is believed ACE can continue operations through 2024.
As of October 2006, 438 peer reviewed papers have been published by ACE science team members. See the
ACE Publications List for more information.
Over 100 Science News items have been released by the ACE Science Center. You can check
http://www.srl.caltech.edu/ACE/ACENews_curr.html for the latest science news from ACE.
For complete mission information, including history and characteristics, visit the
ACE website here. The
wiki site here also has some basic info.