I don’t know of any other such front-ends, tho tof course there will be some more… but IMHO RazorLame is as pretty and functional as you can get.
Remember that in “Expert” mode you choose what options you use (I recommend to do that) so it doesn’t matter what options the front-end offers.
If you are unsure what options to use, you can try to use just ONE option, --alt-preset standard.
This switch in fact activates a whole lot of settings which you needn’t worry about if you don’t know a LOT about mp3 encoding. It’s a VBR mode, gives average bitrates of about 190 kbps (~220 kbps in “difficult to encode” music like metal) and is top-notch quality.
If you want even more quality (and larger bitrates) use --alt-preset extreme or (for the theoretical “absolute best quality that LAME can offer”) --alt-preset insane.
If you like --alt-preset standard but it’s too slow for you, you can try --alt-preset fast standard which is quite a bit faster, and only a bit worse in quality.
Personally I use standard, and I think I wouldn’t be able to hear the difference between “standard” and “fast standard”, but encoding time isn’t an issue for me.
If you want to know more about these switches (and see other choices you may have) visit the forums at http://hydrogenaudio.org. One of the moderators, Dibrom, is the person who worked to refine and include all those “alt-preset” stuff into LAME.