Which is the best software?

Which is the best simulation software for someone with advanced computer skills (i.e. complex UIs don't scare me) but a newb to rollercoaster design?

The ones I know of are: Hyper Rails, No Limit, Scream Machines, UltraCoaster. Are there any others I should be considering?

Thanks!

Well there is RCT3 (RollerCoasterTycoon3) but thats more like building parks and stuff like that but it does have a coastercam.

Well im sure most people will say NL. But if you want a more accurate simulator, physics wise, go fro Scream Machines.

Scream Machines or NL. NL has many tools and many more coasters available, but SM has better FX (imo) and my sounds are awesome (w00t ego), you can find them in the SM Discussion as a sticky (yay ty Edge). SM also has a few extra cars available form toch511, i think his site is torch511.com or something. SM also has a GREAT support editor and although getting a nice smooth track takes time without the tools (it's easy up to a certain extent, about a 7 tech is easy to get), it's still a great designer. SM 2 should be good too, you should email wounded heart's bryan (dragonsioa) and see if you pay for SM1 you get SM 2 free. It should be good stuff.
Anyways, back to SM. The track editor is easy to understand, and although some of the scenery is a bit limited, you should see screenshots for Khufus Revenge, if you want some PM me. It's a FABULOUS coaster with great supports, they must've taken a year jeez lol! SM has a wider variety of trains than NL, including a 4D. The only downside is that it's not popular and it's hard to find coasters. Also, there are no tools (plus or minus depending on what you think).
My advice is to NOT RUSH YOUR DECISION. Take your time. Here's a POV of SM in action: http://mongoose.lp-musix.net/stuff/dfury.zip It's my Dragon Fury. Be sure to check it out!

Don't consider Hyper Rails or Ultracoaster, they're nothing compared to NoLimits or Scream Machines. Between SM and NL, I prefer NL. I won't give any reasons why, because it's a lost cause trying to compare these two great sims. It's based only on what you want from a coaster sim. Both NoLimits and Scream Machines have free demos that you can download, and after trying both out you should be able to make your decision on which game you want to purchase. You can get the SM demo at http://www.wounded-heart.com/ and the NL demo at http://www.nolimitscoaster.com/