Oh, I like this topic! I have mostly grown peppers from your everyday peppers to ghost peppers (the hottest in the world). What I have discovered, as many have already stated, is that HEAT is needed. I found the more common varieties of peppers seem to germinate the fastest at 80-85 degrees Fahrenheit whereas the ghost peppers seem to do best at 85-95 degree Fahrenheit (explains why they're so HOT).

On the note of pre-soaking. Yes, using warmer water is better than cooler water as it speeds up the osmotic saturation of water into the seed through the seed coat. I don't usually do this for peppers though, and it is important to note not to use water that's TOO HOT because it will start to denature the proteins in the seed. Also, don't ever put your seeds (even in water) in the microwave. You will literally kill the seed. I may be recalling it wrong, but I read a study that showed damage to seeds at temperatures exceeding 120 degrees Fahrenheit for lengths of time in water!

Now for my ultimate advice that comes from my experience germinating thousands of different pepper seeds... *drum roll*

I have found the BEST method for germinating pepper seeds involves a heat mat, one of those mini-greenhouse germination stations, and saturating and and allowing to dry the seed. To clarify, I make sure that in the first 2 days I get the seeds and their medium real wet (but not liquored up... jk) set the lid off the base a little to allow the heat to cause the moisture to evaporate rapidly and dry the medium and seed substantially, then the next day or the next time it feels substantially dried out (even if the same day) get it real wet again and allow it to dry out mostly (but not entirely because this could kill the germination process although I have never had a problem getting close to 100% germination). What I BELIEVE this does is create several chances for the seed to trigger by whatever environmental events cause it to germinate! The temperature, moisture, contact with soil, and saturation in the seed fluctuate wildly. I liken this idea to strawberry seeds and how they have to be FROZEN to trigger their germination before being planted in soil. Seeds are fickle creatures, and the experience and patience I have gained from germinating hot pepper seeds has dramatically improved my chances of finding a new friend at the bar on weekends... jk again