I am keen to know people's opinions on Creatine.

Based on your experience, does it work? I have taken it off and on for a number of years and ultimately, I cannot decide. I believe it gives me more energy, but am not sure if it does much else?

There seems to be "some" research on Creatine being linked to hair loss in males. The research seems to be questionable, but it does make you wonder...
I find it effective, though we're talking difficult to measure qualities here; 'energy levels', 'strength levels' etc.

I take about 3-4gm's a day, every day, as well as ~ 700-800gm's of meat, so I'm probably taking in more than I can use, but again - hard to measure.

Maybe it's partially psychological, but then most supplements have that component (those that aren't macronutrients).

I certainly experience the water-retention increase.

Also, Creatine Monohydrate is enough, there's no need to get something described as 'new', or 'better delivery' blah blah crap.
I never really found any noticeable difference in my routines, but I drink a lot of water and eat a fair bit of meat daily.

I did find caffeine and carb's pre-work out did the job though!

Edit: Was taking 5mg/day when taking it.
Caffeine is definitely the most effective of the cheap&legal supplements, although you build up a tolerance pretty quick.
Caffeine is great, if you use it sparingly. As Jester pointed out, tolerance is an issue. It's probably not so good to use all the time, but can be useful that way when cutting.

I find the MOST effective way to use caffeine is use it sparingly, and then right before trying for personal records, take a big dose of caffeine... The nervous system unleashes some serious output on caffeine this way... Lots of strength boost.
One coffee 1 hour before work out works sweet for me (the only coffee I really drink). If I have more than 1 coffee a day it's a rarity!

Tea on the other hand... ;)