the M3 is the best of those rides - period. The problem is ...used ? just need to do your due diligence and checking how well it has been cared for. Also, handing a car like that to your 17 year son ( well nice ) will probably lead to trouble. I got in trouble at 18 with a modified honda civic !!! Not a great car to have for new drivers way too much power..
You will not get the techy stuff that the Lexus and infiniti have in them but you will have a better preforming and handling vehicle. I love and own infiniti's but I think the Lexus has a better look than the G37. All things being equal - for yourself, I would go with the M3, Infiniti, then the Lexus in that order - as for a car I would give my son at 17, I would go in reverse order... ( Lexus, Infiniti, BMW )... see link for comparo...