I too am expecting baby number three...almost 6 years after my second was born!!! Needless to say I have been asking the same question.
I have been given mixed reviews on EVERY swing out there. One thing I have taken away is that the newer swings that swing side to side are NOT always a hit with babies. You either love it or you hate it. My cousin bought a new swing because the one she recieved at her shower just wasn't a good fit for her daughter. She hated it.
My friends are throwing me a small shower so I tried my best to keep registry items to a reasonable price figuring that people can go in together on something pricier like a swing.
Given all of the mixed reviews I have recieved both in person and online here is the swing I ended up choosing.
http://www.toysrus.com/product/index.jsp?productId=436050...
I am not due until May so unfortunately I can not give you a thumbs up or down yet but I chose this one because it can swing side to side AND back and forth. This way my bases are covered when it comes time for our little guy to swing in it :o)
Hope this helps. Godd luck and God Bless!
EDITED: Also, this swing has a plug in option which is awesome because these things eat batteries like crazy. It also folds easily if you need to get it out of the way. There is a short video on the link I posted.