My thoughts...

I would rate L-Glutamine and always have a tub in the cupboard,

60% of the free amino acids floating in the skeletal muscles is L-Glutamine, so it is very anti-catabolic, it helps with protein metabolism and can be used by the body as fuel.

As you may of worked out from the above statement (60%) the biggest and well known aspect is it's ability to limit muscle breakdown which can be helpfull if you are on a cutting phase, or "limited calories". I have even read reports where L-Glutamine is being used in hospitals to replenish the body after stress or trauma!

As a few of you keep pointing to studies, one such study showed that a 400% increase in growth hormone levels was shown when as little as 2g of the free form L-Glutamine was consumed.

There are no side effects associated with L-Glutamine, because it is a nutrient naturally found in the body but is depleted after the body is put through stress, as much as 50% can be depleted after intense training. I take 5g am - 5g Post - 5g PM and have done for some time now with no problems with upset stomach or such, but with all supplementation you should increase gradually.

When taking L-Glutamine, the First dose should be in the morning before breakfast in water for maximum transportation.

L-Glutamine cannot be taken at the same time as creatine as they both will compete for up take, so one will be excreted from you body WITHOUT BEING USED.

As for Energy pills, some of these work well, but I would also follow DaveMC's advise or...

....you should try say a strong and I mean strong cup of black coffee before you throw ya money away....this can be effective taken 40mins before a workout, ok it don't taste that good but can also help release the fat adipose tissue and help with fat loss as a bonus!. Many bodybuilders will take a strong coffee before AM cardio on an empty stomach to speed up the fat loss process.

Now the ECA.....Sod the studies.."it does improve performance", I'll post you 2 Dave
well it must be one of the most well known which I'm sure many on here including myself have used is the ECA Stack...Ephedrine Caffeine and Asprin, which was banned for some of the reasons stated by DaveMC...If taking this stack you should not exceed the stated dose, access your tolerance before taking the stated dose, and make yourself aware of the side effects if you abuse this substance! This Stack will supress your appetite and you will become dependant on them after a long period, do not take them after 1pm if you want to get to sleep at night!!. If you did manage to find some, it is out there!.... it must be the most effective thing you could use, but I am NOT recommending it, I would like to make that clear!

Sorry turned out a bit long that, but will be of interest to some.