I usually just use the OBDII reader function of the Torque app on my cell phone with a OBDII to bluetooth adaptor. Pretty inexpensive, but limited to just reading and clearing falt codes.
If it is something harder to troubleshoot, I borrow my friends Snap-on "red brick" as mentioned above. Only used it to figure out the LH 3.5L had a leaking intake manifold gasket.