Still guitars…
So what should you look for in a new guitar?

Some of the things you should consider buying a new or used guitar are imho:

Technical stuff like
a good neck – hold the guitar so that you can look down the length of the fretboard and check wether the neck is twisted, or if frets stand out too much, Play every note on every fret, to check for bad frets (if you look down the neck along the frets, it should be a straight line, there should be no bumps or curves, best way to see this is to press the e-string down on the 1st and last fret and compare the shape of the neck and fingerboard to the straight string) this is one of the most important things, if the necks not allright, repairing it will cost a lot of money; if single fret are loose and stand out too much your repair guy can carefully hammer them back in with a fretting hammer. If you really want to do it yourself use a soft face mallet only! If you use a regular metal hammer you will damage the frets, which will lead to more expensive repairs!

tunability – working tuners (should tune without “jumping” and stay in tune -> a well adjusted/sawed/lubed nut is very important for tuning as well, easiest way to lube the nut is just rubbing a sharp pencil in the slots), octave adjustment, check chords in different positions (if they sound bad the string saddles of the bridge have to be moved to change the string length a little bit; check the fretted note at the 12th fret against the harmonic at the same fret; if the fretted note is too high move the string saddle away from the neck, if it is too low towards the neck, retune, check again)
string action – is it low enough for your style of playing, but high enough for the strings to vibrate freely
functioning vibrato (if there is one of course) – does it stay more or less in tune, does the whammy bar feel right, is it fixed right (not too loose but easy to move around without rattling)
electronics – test with an amplifier, check out all switch positions on the guitar, with cleansound and distortion, check with heavy distortion for hum, feedback and microphonic pickups (squealing), a certain amount of hum and noise must be expected from singlecoils, but the combined sounds should be relatively hum-free (you can add shielding to a singlecoil guitar by adding selfadhesive copperfoil or use graphite laquer, be sure to connect all parts of the shielding to the ground, it will reduce the noise; if the pickups squeal, which can be very annoying, you can bathe them in hot wax, never did it myself, but had a tech guy do it on the pickups my Epiphone Genesis)

Music stuff like
does the guitar inspire you?
Can it produce the sounds YOU need for YOUR style (like fat powerchords and leadsounds for rock, or stratlike cleansounds for pop and funk…)
does it have the tonal qualities you need – Singing single notes, even sustain (no bad “dead spots” where notes fade out very fast), transparent chords, or maybe a tight low b-string
is it versatile or a one trick pony (both can be good)

Personal stuff like
does it look good,
can I afford it
will it get me psyched when I pick it up?
(weight is also very important, if you get an aching back from your rocking guitar, you probably will get rid of it sooner or later but then again some heavy guitars just sound very good :-))

If you can, try different guitars, even from the same model, as most instruments are made out of wood, the tonal quality will be different. (don’t buy the instrument from the shelf, but the one you tried, a student of mine checked out a guitar and the got “the same” only that it was faulty)

If you dont feel like you’re experienced enough ask a friend to give you a second opinion.
If you’re buying at a store try checking out the dealer, is he just selling something, or does he answer your questions well, does he show you alternatives or just push you in one direction, of course there may be dicks selling great guitars, but if you’re treated arrogantly be cautious. Don’t let yourself be bullied into buying a guitar that is not perfect for you.