Such websites probably work best if you take a contrarian approach, unless they actually can compute the hashing power on a coin by timing the blocks or something.
If they just look at the difficulty, which for some coins won't change for a long time, then probably when the difficulty goes down so many miners jump on it imagining it is profitable as reported by such sites that actually you are less likely to find a block than when difficulty is higher and all the miners move elsewhere.
Plus the exchange rates too are probably misleading, as a good rate is not something you are likely to get in a few hours when you have actually managed to mine some of the coins, it is something the people who already mined them back when such sites claimed they were "unprofitable" that have coins on hand to sell that those good prices. By the time you actually mine some - assuming you even get any since the whole gangbang crew will all be there too all thinking it is "profitable right now" - the exchange rate will be back down again from people who already got the coins skimming the good prices.
So doing pretty much the opposite of what such sites indicate is very likely more lucrative than following the lemmings who believe such sites.
The one thing they DO have right is merged mining gets you more profit than mining only bitcoins, but they leave out four of the seven (or is it five of eight) merged mine able coins so you don't see all the goodies merged mining can get you.
(CLC and XGG should be shown on the
http://galaxies.mygamesonline.org/latestrates.inc readout next time it is generated, maybe that will help some.)
-MarkM-