If I'm not using the guitar sim's reverb, I will probably use convolution or Breverb CW edition.
Speaking of, I am really impressed with the reverb in S-Gear. It just does so many things so well.
Also, Guitar Rig's Vintage Verb is really nice. One trick I recently discovered is to use the Octoverb's "Guitar" preset with a short time and mixed low or against another verb to give a bit of life to rhythm guitar.