well, i think the main reason i love the show is its coziness factor!! think about it - the brightly lit hallways and workplaces, everyone walking around in their pajamas, the constant and soothing humming of the engine, the stars are always out... i just want to jump in the screen and live there! i loved the entire cast nearly equally, so i'll list my favorite guests: Q, Kern, Damok, the traveller (i heard he has great insurance) and the dude who escaped that prison planet.
STNG was by far the best trek of them all. lots of people outright hate the characters of wesley, beverly and deanna, and, while i agree they are not the best characters, they are so much better then major kira, sisko, dax, neelix, janeway, and kim, all of whom are either entirely devoid of personality or are irritating to the point of destraction. i mean cmon, i got so tired of kira's constant state of agitation that i stopped watching the show for quite a long time. i know a woman like that in real life and let me tell you, she is no fun at all. shes never really worried, or happy, or compassionate, or loving, or funny, or silly, just ANGRY. i also dont like the gloomy lighting used on those shows. so, to sum up, STNG is a timeless classic i will never get tired of!