Plasti-Kote textured spray. I also read a really great post from Miniature Tim about sprays so I thought it would be good for me to say a few words about my experience with Army Painter Desert Yellow which I've been using to try and get quick and consistent results on my Imperial Guard tanks (what do you mean you haven't seen them!?). The spray itself is actually very good, with great coverage. Although you can in theory use it on bare models, I use it over a black primer and this allows me to control the amount of colour that gets shown through. This is great for creating natural shadows.
You do have to watch out a bit as there tends to be a fair degree of dust scatter. The missus was not too pleased about the redecoration attempt of the outhouse, nor the fact that everything in there seems to be covered in a fine layer of sand coloured dust. Good news is the dust just wipes clean... though the wall will need a new lick of white paint.
However, this really is the least of my issues. Because whilst the coloured primer certainly has made things quick, it has definately NOT been consistent. The colour variation from order to order has been pretty obvious. At first I was pretty disheartened, although have come to live with the variation in colour between tanks. If I were painting something like Eldar or maybe even Space Marines then it would be highly unacceptable, but lucky for me the Guard probably aren't known for their colour matching prayers. The control-ability of the spray has gone some way to help me mitigate the colour issues.
The Army Painter Lottery? 3 different colours from 3 different cans!
I'm going to stress that this is only relating to the Desert Yellow. I have no experience with the other colours (of which there are many) and so I can't confirm or deny that those other colours have similar issues. Another thing to be said is that I also use the Army Painter Quickshade, and that you can use this to help equalise the differences if need be.
Despite that I would definately recommend using Army Painter sprays, but with the one key warning that you should wherever possible, order enough sprays to complete your project in one go. This will help ensure that you get cans from the same batch! I manage to get something like 7-9 tanks out of each can, so plan accordingly and you should be fine.
In the end, I'm glad I chose Army Painter, as I'd have had far more trouble trying to get my tanks done without it! You can check out their full range on the Army Painter website.
Perhaps not exactly a glittering review, but you can check out what you can achieve by looking through the Gallery.