Disc Brake Rotors - which ones...?

fairly new/inexperienced with disc brakes (in terms of different models used/swapping and changing) have recently stuck with Shimano as they are easy to bleed. however, i havent paid much attention to the the type of rotors i use.
the ones i have are tektro wavey and some odd shimano ones.
i see a lot of skinny/light looking ones but can't tell who they are made by and which ones to avoid etc...
i'll be using mainly for commuting, but will want something decent for the occasional trail ride.
are there ones that are more corrosion resistant? i cycle on the coast, so lots of salty air to contend with.....
any suggestions or advice before i start trawling ebay/CRC/rosebikes......

If you're doing commuting and the occasional trail ride then I doubt you'll need fancy floating rotor designs or massive discs. I use 160mm up front and 160 or 140 at the rear and this is all I need for general MTB riding.
In my experience cheaper usually means heavier, but I don't think there's anything wrong with Tektro or Clarks discs to be honest.

I do like the Avid G3 Cleansweep rotors (that are supplied with Avid brakes), they're not fancy, but I've never had any issues with them.

If you want lightweight then look at Ashima discs (Air Rotors), I've used them in the past and found them to be quite good. Some say because there is practically more "holes" in the disc than actual metal material then the braking performance is not so good, I didn't find this to be the case. Nor did I find the pads wore down quicker either, another comment sometimes made.

I take it you need 6-bolt rotors? If you like Shimano stick with them, otherwise I'd probably be looking for some bargains on CRC.

Avid G3 offer good value - reasonably light, good stopping for not too much cash.

promax offer the same as the above but are lighter at 96 g.

there are alloy carrier disc brake rotors, the cheaper ones are actually heavier than the above.

ultimate lightness are KCNC razor - these at more air than metal and I find do nto stop as well.

i have recently been converting to these - seem to be one of the lightest rotors around with decent stopping power.
http://www.xcracer.com/shop/viewproduct ... ductid=299

Which shimano are they ? theres a world of difference between alivio ,the different deores ,and the higher end like XT XTR Saint brakes.

doon the coast eh :? well im unsure but i think most rotors are stainless ,the decent ones anyway ,so stick to say proper shimano or Hopes or whatever you know for a fact is stainless and buy that.

As to skinny rotors ,im of the camp [oo-er] that the more metal on the rotor the better grip the pads have. There is the scenario that the pad grips and the rotor folds back on itself :? Pics of it somewhere.
A 185 on the rear with 185 on the front is probably more than enough for commuting but better it there than not, and it saves swopping it over it all over adding adaptors and general annoying farting about when you dont need to

Consider if you are commuting in a hilly area and fether the brakes on a decent overheating with small rotors can be an issue. 180F/160R is a good set up for all types of terrain except for proper DH riding.