Periactin (Cyproheptadine) is somewhat effective in making it easier to achieve orgasm whilst on SSRI's. If you can stay awake on it that is.
Its an over the counter anti-histamine but it is quite old so a lot of pharmacies don't carry it. You might have to shop around a bit.
Periactin + a couple of dexies used to do the trick for me. Other than that you could always discuss changing your SSRI with your doctor. The sexual side-effects of some are far less than others. Of course this has to be balanced against the efficacy of your current drug in treating the condition for which it was prescribed. If another SSRI will let you cum but isnt as good for your depression/anxiety or what ever well its best sticking to the old one.
To be honest, unless you are in a long term committed relationship, why not just enjoy walking round with the knowledge that you are a super stud and can satisfy even the most stubborn of women (assuming you're male of course)