I like TNG, but I find VOY much more emotionally affecting and also a lot more fun, generally. These are the reasons I find it to be so similar to TOS. While I admire DS9, I have never felt connected to it emotionally. VOY is full of poignant moments that directly engage the viewer in a character's personal conflicts, usually centered in some deep-seated pain, flaw, or memory. (True of DS9, too, of course, but as I say I find VOY more affecting.) On TOS, Spock's difficulties with his identity were similarly painful and poignant.