Is there anything they do? My Amplitube and Guitar Rig sound like shit! lol,
I use my fender stratocaster through my saffire pro 14.
Learn to tweak knobs? Don't really know what to tell you...

Never been a huge fan of Amplitube or Guitar Rig myself, but you should be able to get something passable out of them. Try the free amp sims by TSE, LePou, AcmeBarGig, etc. You might find you like them much more.
Quote by Dave_Mc
I've had tube amps for a while now, but never actually had any go down on me
Quote by jj1565
maybe you're not saying the right things? an amp likes to know you care.

Read about impulse response loaders in this thread that is for some reason not stickied.

Amp settings with mids around 7 (2 o'clock), highs around 5 (noon), and lows are 3-4 (9-10 o'clock) is a good place to set eq. turn your gain down a little lower than you think. Then double track it all (as seen in the thread).

I would try free amp sims as they usually sound better in my experience specifically Poulin and TSE plugins.