I have just come off meth amphetamine after a year of heavy use and I'm two weeks clean and feel fantastic. I find that smoking cannabis (both sativa and indica) provides me with that rush that you would otherwise experience from crystal but without the negative repercussions such as the riggles and shakes when you don't have any meth in your system.
I like to keep my cannabis consumption moderate and infrequent. Organic and preferably grown outdoors. I'm sick of purchasing cannabis from dealers who you can't trust and whom might taint their product with other chemical substances.
If you are after an energetic strain you can't go past a pure sativa or very high sativa dominant strain like Nevilles Haze.
Best of luck buddy