I prefer the SL9 and Fischer World Cup SC out of the ones you listed. I've used the SL9 as my primary slalom ski for the last couple years, but I'm moving to the WC SC for next season. It's slightly stiffer, but nowhere near the Fischer Slalom, which is too much ski for me most of the time.
I picked up a pair of iSLs (non-chip, race stock) for really cheap, but didn't like the feel of them. Likewise, the Dynastar recreational slaloms didn't thrill me either. This is probably a side-effect of skiing on Atomics and Fischers for so long, but if it ain't broke...
The Elan SLX is another really fun ski, but it isn't always as easy to find as the Atomics and Fischers.
Right now Atomic slaloms are going for much less on eBay because of next year's binding change. Fischers have been holding fairly steady because they don't require a specific binding.