Personally i can't stand fan service, I understand that in the comedy shows it goes well with the humour for people who like it but in shows like Neon Genesis and GitS:SAC it just gets on my nerves, it's not needed and takes the class away from the directing and makes it appear childish.
It's like Matsumoto from Bleach, yeah in Bleach theres a lot of fan service anyway but thats her soul reason and purpose in Bleach and i really can't stand her. I just don't find people getting embarrassed by big tits on the verge of falling out funny at all.
But each to their own i guess.
I like the argument that was brought up by someone who stated that if it was live action would you feel differently towards it, because yes i would depending on what i'm watching if it was something serious then i'd seriously question why on earth the director put that shot in but if it was a comedy i'd gladly stare. I guess its something to do with the fact one's real and the other isn't. I just prefer my anime more mature.
My friend brought round Tenjo Tenge and i couldn't watch it after like 1 episode, killer fight scenes but the fan service was just ridiculous lol.