I tell my private guitar students that the first thing they should do every time they pick up their guitar is to check the tuning. No matter how good of a player you are, if you are out of tune, you will sound terrible.
Brand new students come to me and ask for suggestions on which tuner to buy. For acoustic guiatars, I typically recommend the Snark Guitar Tuners.
For electric guitars, I like the Korg TM50BK or the Boss TU80. If you want a great stompbox tuner to add to your pedal board, check out either the Korg Pitchblack or the Morley Accu-Tuner.
What about the times you find yourself without a tuner or want to explore some free options?
3 of my favorite free tuners are
Gibson Learn and Master Guitar tuner app. The Learn and Master Guitar DVD series is one of the best methods out there for learning guitar and they have created a free app for your smart phone that includes a tuner, metronome and some other cool features. Click the banner to check it out.
Marty Schwartz of GuitarJamz.com has a cool tuner app as well. In addition to the tuner, the app comes with 5 free guitar lesson videos and a guitar chord ebook.
And finally, one of the biggest and oldest online methods of learning guitar, JamPlay has a cool online app for tuning both acoustic and electric guitars.
Click the image to check it out