Widgnwhacker,
There are already tons of good suggestion, so I will just give my 2 cents in terms of performance.
Depending how much you like to spend, I'd strongly recommend a sammie from Shoppe (the Lux I RY0J MM lite) for around 30 as compared to the old Terralux TLE5 Ministar 2 (around the same price).
The new version of the TLE5 might worth a try since it is using the high dome, but personally, I like the tint color of Y0 and feel quite comfortable knowing that it is a tint that I like instead of doing a 'lottery' from TLE5.
As for less expensive options, from what I read, NiteIze is quite a steal at the current price level at Walmart. But Opalec do have a better feature of low battery warning at a hight price, but the regulation is great.
For more details about various other kind of mods for minimag, please do feel free to check out my humble writeup at Dummy Reference Guide to
Minimag mod