if you're looking for a strong, cold menthol kick, mreliquid.com's "ice" series ought to do it. coldest, strongest menthol i've ever experienced. i haven't tried their straight menthol, but it's their best seller.
I'm a menthol only vaper and I have three ADV's - they're all from Mr E. Liquid's ice range... pure menthol, banana ice, and grape ice. His apple ice is pretty good too. Haven't tried his full range yet. However, none of his menthol juices come even close to the iciest I've ever tried, and that was Rockstar Vapor's Menthol. Iciest on the market, according to the 20-30+ I've tried to date. So icy its too strong for most people I suspect. I LOVE it. See, I've talked myself into ordering more, that's how good it is.

Here's a friend on youTube trying it for the first time:
J's Vape Reviews- Rockstar Vapor Mint Flavor Extravaganza - YouTube
Prothol is nice, not strong, smooth, with some subtle undertones. Minthol is good, but a warm vape so it reminds you of Vicks vapor rub... great for winter vaping. Mr. E. Liquid's is not too strong, but refreshing. At this point, he's got me as a regular customer, so I also recommend his ICE line.
I think its time I picked up some crystals too, as jamentertainmentri recommends... I've got about 20 non-menthol juices beginning to age (5-7 months) that I just can't vape due to the lack of menthol. Yes, I was a 17-year smoker and the last 8 of them were menthols only.
