country acoustic and electric.
Although you will never convince a guitarist that MIDI guitar sounds realistic you can come close. Note guitar isn't the only hard instrument to emulate as all the saxes, woodwinds and horns are also very hard to emulate.
First the easiest way. Convert your MIDI guitar part to a wav, then run that wav through Amplitube. Keep trying different amps and effects to get what you want.
The hardest but best way is to learn about MIDI controls, especially pitch bend and modulation, ie the mod wheel, also called CC1. This can add a lot of realism to a MIDI guitar. Then repeat the first step using this modified MIDI track.
One of the best things about MIDI is that it is very modifiable. You can change pitches without artifacts, add effects like vibrato via the pitch bend, as well as a ton of other things. The bad thing about MIDI is that to get the most out of it takes two things, learning about controlling MIDI and to get better sounds cost more money. MIDI sound source prices go from zero to thousands of dollars.
If you are really interested about MIDI I would suggest one of two purchases, i.e. Kontakt or Sample Tank 3. I believe Sample Tank 3 is only 64 bit so jBridge will be necessary when using BiaB or RB. Of the two I chose Kontakt as it has a lot of third party sounds for it with many very reasonably priced. If you are thinking about either wait until there is a sale. Many times they go for half price.
I hope this helps and good luck.