Jean,
I don't know if you've heard of the alternative/rock/metal band TOOL. They are very popular in their genre and use a ton of "weird" time signatures in their music. It is not uncommon to find 9/8, 7/8, 5/8, 5/4, 6/4, and 7/4 in their music. They even will sometimes alternate the time signatures from measure to measure to give the riff a very "unpredictable" feel. Mike mentioned earlier in the thread that each of these can be divided into subdivisions of duples and triples and I've found this valuable to be able to count these depending on how fast the tempo.
Here are a few others:
Tchaikovsky Symphony No. 6 2nd Mov. 5/4 (5/8)
Shostakovich Fugue No. 15 (Alternates 3/4,5/4,4/4)
Led Zeppelin-Four Sticks (Verse 5/4, (5/8))

Jeff,
I have Finale 2005 and I love it. Most people used to say Finale was better for Midi music creation, but I produce pretty good scores with it. Sibelius, however is the motherload of all music scoring programs. My composition professor uses it and I found that there was a large learning curve for the use of the program. The playback of the parts seems to be much more realistic on Sibelius though I haven't heard Finale 2006 or 2007's playback. This for me is one of the most important features for me. Especially when writing for instruments I don't play.

Nate

http://www.youtube.com/watch?v=aleDoNlSdCs
http://www.youtube.com/watch?v=EXE4LXl4_M0