I didn't know quite the appropriate place to put this, and think "Other Sex Topics" might be more appropriate, concerning more than pleasing me (although that is the main concern), but that topic gets less attention.

I'm not new to sex. i'm not a seasoned veteran either though. Right now I've been sexually active with my current girlfriend for almost three months now, which isn't too long, but a lot has happened in that time. The sex is awesome, and the sex is quite abundant. In previous sexual relationships, I'd had trouble orgasming to sex with my partners, which is, i've figured out, relatively rare. I still have trouble orgasming in this sexual relationship, but not nearly as much as previous times. Now it's more like having outstanding stamina rather than wondering if i'm ever going to orgasm. So my concern now is with variety rather than finding a way to make me cum.

We've tried many sexual positions in the last few months, from her on top to spooning to variations on missionary, etc. But it seems that the two that bring me much pleasure are missionary and doggy style. These two positions are also the only two that seem to be easily maintained over a long period of time. So my search right now is a search for viable sex positions that would bring me adequate pleasure while mixing it up a bit to keep from allowing boredom and routine to set in.

My problems with some of these positions:
spooning-i don't get enough leverage to be able to thrust very well. We have to maneuver very carefully to keep me from slipping out as well.
her on top-this is pleasurable on occasion, but oddly enough she gets very little pleasure from this position, making it unfun for her. plus, sometimes the rhythm that she gets going feels like it will break my penis, and that kind of pain isn't good during sex
reverse cowgirl (her on top facing away)-feels ok, but we're pretty intimate, and this does away with intimacy almost completely.
i've tried different variations on missionary, like her legs over my shoulder, and these work occasionally, but it's all still basically missionary

I would appreciate any thoughts or ideas. I just want some new positions to try out that don't easily let me slip out and are ultimately focused on my pleasure. Thanks

(many may wonder why i'm worrying about solely my pleasure, seemingly neglecting my significant other. fear not, I give my share of pleasure [:p ]. and she gets at least as much pleasure from missionary as I do, and we've gone nights where she's had half a dozen or a dozen orgasms and i'm still going, so pleasing her is under control, i just need to pleasure myself now)