Any of them will do:

Max
Viz
Cinema 4D
Rhino
Lightwave
Maya
Softimage
etc.

Plugins for rendering:
Final Render
VRay
Brazil
Maxwell
etc.

But what it really takes is a good eye and good knowledge of the software. A skilled artist could make a great rendering with any of these software packages and a bad, inexperienced artist will not make a good image regardless of the software.

The most popular is 3D Studio Max/Viz, with Final Render or Vray.

I conquer with trace.

I personally prefer working with Maya 7 and Max. I've also found that Photoshop is a great tool for tweaking colors, etc. after rendering.

Never used 4D or Rhino, but I've heard good things.

If you know no software (or is it no know?) I would suggest you learn Rhino and use Flamingo to render. It is pretty intuitive. Attack Maya a lttle later in your 3d life...

i like rhino for modelling. as garpike said it is pretty intuitive; the most of any of the modelling software packages i have used. the rendering software flamingo is ok but i am ready to move on to something new. outdoor rendering is decent, but interior spaces are far more difficult to light well.

I find that the software i use depends upon the kind of modelling/rendering i want to do.
For example:
1: I use Autocad or Architectural desktop for simple rectilinear kind of stuff, coupled with 3dsmax and its plugins for rendering. For your typical architectural rendering.
2: For complex modelling of curvilinear/ruled/other surfaces, i prefer to use maya, and render in Maya using Mental Ray for sharp/shiny images. Typically for projects of an experimental nature.
3: I use Rhino when i need to add complex surfaces to simple models, also, to make shadows in plans generated from 3d models, and to make phylogenesis(foa's ark) kind of renderings.
4: permutations and combinations of the above.

A small amount of post processing in photoshop almost always helps.

P.S: To CONQUER(i mean really conquer) the world of architectural rendering you should know at least half of the software trace has mentioned. My personal opinion is that you can do better stuff when you know a little bit/enough/intermediate level of most software and are not a crazy scripting kind of expert in any one. May work different for others.

having never designed anything that was not at least planar, i cannot concur from experience -- but ret is right on, it's more important to know how to learn software than to know the software. because the software is always changing AND if you learn a few tools then you'll find yourself taking the best from each and making your life easier. personally i'm a dummy, i do most of my 3D modeling in autoCAD (only tool cartesian enough for my left brain) and then export the stuff into form-Z where renderzone makes it look just real enough for the client to say, oh yeah, i get it

I have a question for you guys. Do any of you create the model in AutoCad and then import it into Max to add materials and render?

i used to do that

I only create some of the 2d in Acad. All modeling I do is in Rhino. I have never modeled in Acad. I started modeling on formZ (way back in 1999. Or Pro-E way back in 1995, but that wasn't architecture...).

wow. and i thought photoshop was the way to go..

How about first vanquishing your atrocious spelling because it will be an almost insurmountable task to beat Zaha who has already conquered the universe.

I've been doin' this since I started CAD+Max...:

> model in AutoCAD, work like layers are = to materials
> import architectural elements in small portions to Max (even if they form part of the same material) so you can later define easily different kinds -or same kind but with different light exposures- of concrete, wood, metal, etc.
> render preliminary views w/o lights & textures to find which ones explain best whatever you want to explain
> add or delete un/necessary 3D elements when you have the right views saved (go back to AutoCad if you have to add complicated forms or model them in Max if they are simple -cubes, spheres, etc.-)
> then, finally, add textures
> then lights (go back to redefine some textures -w/ Photoshop- if the lighting alters too much the colors or 3d effects of some textures)
> final rendering in .tiff
> open the .tiff in Photoshop, play with it 'til you're satisfied with the results
> save the final view in a small .jpeg to deliver -keep the large .tiff for possible future modifications-

its a long -and a little bit complicated- process at first, but not that difficult once you're familiar with it.

suture, i concur.