I guess after reading all the replys here, you can tell that a lot of the guys will enjoy pretty much anything
But there seems to be a devide on the teeth issue. Personally I prefer no teeth, but I guess it depends if the teeth are sharp or smooth. My GF's teeth are quite sharp, so its not something I like to have grase the head of my penis.
I have had teeth used before and its been quite nice, but for me it always feels too much like a dry moment (in the sensation it gives).
Spitting is something I really don't like to see, but its more the sound that is made. The same goes for deepthroating, results in too much gagging/sound and oftern lots of drooling. That for me is a big turn off.
What turns me on then, well for the most part knowing that
SHE wants to give me one is a big turn on. Maybe its because its feels like I'm not nagging for it (not that I do ofc), or its the fact that I know she'll be enjoying it as well.. sometimes I know she does it as a dominative roll. She knows she is giving me pleasure and has control over making me cum, if at all.
There are times where she'll crawl up to me while we're watching tv or a movie on the sofa, get my penis out and start sucking away until I'm hard and then leave it; go back to watching the TV until I get soft again.
Blow jobs usually consist of a lot of head and a bit of ball work. I'm not too sensative on the actual shaft of the penis so we tend to leave that alone.
The head of the penis, is licked much like you're licking a lollypop or icescream on a cone. Around the ridge of the head where its darkest in colour is the most sensitive part for me. Using the tongue around there and puckering up the lips (as to kiss) while moving them just over and around that part of the head is really nice.
The top of the tongue where it's roughest makes a really nice texture to rub along the top of the head, in twirling motion.
Moving around in a 90 degree motion while going up and down on the head of the penis create a nice effect, much like the twirling of the tongue. This same effect can be used to masturbate using the shaft of the penis, and usually results in pusing me over the edge a lot quicker so is good for quickie blow jobs.
The balls are nice to be caressed, shuffled around in the sack (something you'll have to take your time with here as they're all different and some are VERY sensative from what I've heard) mine are quite fine and I can enjoy them being squeesed and the sack being pulled and stretched (the inside of the legs are also nice to be scratched too). Rolling the skin between the finger and thumb and using finger nails to scratch the skin is nice.
Although it won't be nice for all men at all, I enjoy having one ball sucked into the mouth and the tongue rub it a bit as I continue to be jacked off.
Finally, when I do cum I much prefer to do it where most of the action as taken place that got me at the point of no return. When I say that, I mean if I'm enjoying having a blow job where the head of my penis has been in the mouth using circles around the edge of my head when I get the urge to cum, I'd prefer it if that was contiue to happen until I come (and sometimes for a little while after).
Other times, if I'm having my balls played with and simply being jacked off, I'd not prefer to have my head suddenly covered up when I squirt just to get it in the mouth. The change of temprature, texture, wetness etc is usually something that puts me off the enjoyment of cumming.
Something that really turns me on more then anything is the 'look' she gives me direct into the eyes as she looks up to me with my penis in the mouth. She can't talk, but her eyes says it all. I'm sure some girls can tell you more about how to perfect that look
Another thing; my girlfriend doesn't like cum in her mouth, its taken a few years for her to take a squirt in the mouth while giving blowjobs, but a tip she learnt is to use the bottom of her tongue on the top of my penis to stop the cum from shooting down the back of her throat. After that, she just expells the cum either down my shaft or uses a towl wipe her mouth. A glass of water by the bed helps.
Communication and experimentation is the key, try new things, include things you know will work and get him to tell you what he is enjoying. A lot of the time he wont know himself if hes not used to telling you what he likes or doesn't like.