I used the Ralph Lauren River Rock textured paint in the dining room of my old house. WARNING: it's a lot harder to work with than regular paint. You can't just 'spot fix' because the texture will show the fixes. You should absolutely get the right rollers, etc that the paint recommends and be real careful during the 'cutting in' process to not get any streaks with the brush since it's hard to fix.
The results are great, but it is time consuming and it took about three coats for us to finally get it right.
With imperfect walls, you could also try some faux techniques (like ragging or sponging). It, too, does a lot to disguise some of the wall's 'warts' and in my opinion takes less time.
Best of Luck to you.