The LG is sorta impressive in its way (camera MP, screen). The SGS3 or the Note 2 are better all around better devices IMHO.
If those are your three choices, then it comes down to it the 5.5" vs 4.8" because the N2 and the SGS3 are just 2 sizes of basically the same phone. The n2 does have the quad core going for it plus all the phablet extras.
I would choose the SGS3 only because I am not yet sold on the 5.5", and I had that option last week.