I have 4 currently:

1959 Gibson L7-C which was my first real guitar. Play jazz stuff
Late 80s Alvarez-Yairi CY-116 Classical. Play classical stuff
1991 Gibson ES-165. Play amplified jazz stuff
New Martin DC-16GTE. Medium width neck means I can almost play any style on it amp'd or not which makes it convenient for playing out.

Other than the L7-C my wife bought them for me so I guess I've explained the need enough. Had a 12-string but I gave it to a niece last year because I'm not strong enough to play it anymore anyway.