Meth has a very "speedy" effect, you're very restless, (too) talkative, unable to just sit back and relax. The mind and thoughts rush through you're head, a strong urge to do something. Unable to sit still, you're hyperactive. Have to move some body part, usually legs and hands.
Coke has a more mellow feel to it, giving a huge ego-boost, basically more subtle than meth. You're not as hyperactive on coke as on meth, it feels good just to sit back and talk. And since you're the king of the world on coke, you have a lot to say. You don't always feel coke as clearly as meth, as it is...well, subtle is the best way to desribe it.
I personally find that the first few lines of coke are not that euphoric, but after that coke is far more euporic than meth. Coke also make some people idiots and aggressive, especially in combination with alcohol. This has to do with the ego-boost, I know of no other drug which kicks your ego up as much as coke. You're just extremely self-confident.
In my experiences, meth has an absolutely horrendeous comedown. On coke, I've never had bad comedowns. The urge to re-dose is quite high on coke though, I'd say it's much more addictive.