Good ab workout needed

I really need to concentrate on strengthing my abs.  I am 2 years out, have been going to the gym for 1 1/2 years and now need to get my ab muscles ready for a TT in 4 weeks.  Any suggestions for the gym? Any links?  Any help will be greatly appreciated. Thanks Sheryl

I really like the Tae Bo bootcamp Abs workout. It's nice since it's not all floor exercises.