i use sony vegas movie studio 9.
its a great piece of software , but it does need to be updated to the latest version online. the update is over 70mb's so you
need a decent isp to begin with. the program only cost me around 40euro , but it should be cheaper now due to the new HD
version they just launched .
it really is a great video editing suite. its extremely easy to use , especially if you have previously been playing around with windows movie maker.
the effects and keyframing are also easy , but if you have no experience , there is a guy on youtube who does amazing tutorials.
ive learned so much from him,
http://www.youtube.com/user/guerillabilli reccomend this software highly. its optimised for dual and quad-core cpus also . so when rendering, it uses 100% power
to get the files done faster. however, some people do have problems with it, and sometimes its a bad codec and or rendering probs, etc , but its good software overall.