Personally, I've found benzo's to be the best for severe nerve pain. I know, I know... benzo's are addictive etc. But seriously, they provide no euphoria (to most people anyways) and I almost never abuse them (I've found them not be psychologically reinforcing at all). Physical addiction is just a side-effect of benzodiazepines. If you take benzo's for more than a couple weeks straight - you will become physically dependent. There is no way around that. However, you will not be psychologically addictive if they are taken correctly.
Anyways, I tried everything for nerve pain. Tons and tons of SSRIS, SNRI's, Channel Blockers (which were the most effective non-controlled substance Rx drugs), antipsychotics and TCA's (both of which just made things a lot worse), and many other drugs. I was prescribed codeine for a small amount of time, but found it be ineffective after any sort of tolerance built up. But benzo's did just the opposite.
I've found that they've made my RLS and nerve pain way better as time has gone on. I no longer suffer RLS during the day, and while I would have RLS at night - the benzo's I'm prescribe for sleep stop that from happening. I no longer have to live my life in physical pain because of exhausted nerves or whatever the fuck causes nerve issues. Also, I've also found benzo tolerance to be no where near what other people have described it to be like.
Maybe that's because I don't abuse my prescriptions? Who knows... All I know is that I've been on Benzo's every day of my life since last August and they're still 90% as effective as they were when I first started taking them.
An exception to the only thing helping for nerve pain (that isn't a benzo) is Nicotine. For some reason, Nicotine has always taken away all of my nerve pain. It's incredibly effective at doing so. I wish doctors would look into this further (explore nAChR as a means of analgesia) because it seems to really work for me...