JESUS NO! Dont take anything that is cough n cold... The cold part contains drugs to dry out your throat and in large quantities it will hurt/damage/kill you. For the love of god go here
http://www.erowid.org/chemicals/dxm/dxm.shtml and read up on dangerous active ingerdients, side effects, and dosage.
For taste i recommend plain ole robo, its not quite as bad as the genric stuff and a hell of a lot better than vicks 44a. Also for doseage, stay with in the normal range..about 350 mg (about a 4oz bottle of robo @ 15 mg dxm per 15 ml or somehting)...and you should be fine. You'll have to do a little math to figure it out, but then a little math never hurt anyone. One time i took about 600-650 mg and lemme tell you it aint fun at all.
As stated at erowid only take pills/syrup that have only DXM as an active ingredient. If you are in a hurry just scan the boxes that say cough only, if it says cough n cold or cold n flu, whateva, it aint good for you.
Also about the damage done by dxm, Its about as harmful as 'a weekend of binge drinking'. The sugars and thickeners will play hell on your stomach, pancreas and other fun internal organs.
Oh yea, as to how they make you feel...
A moderate amount will feel (or at least made me feel) sorta like taking xtc. a little more artificial and greasy though. I had a lot of energy, kinda tweeked, had to listen to music and the tv. it felt good to dance and jump around and i wanted to find someone to latch on to...
A lot is a whole differnt story though. 600-650 mg is prolly more on the pcp side of the dissac. fam. I couldnt remember if i was awake or dreaming, I'd do some thing, fall asleep and dream i did it three or four more times. Everything i saw was double but i had no visuals. I was sick to my stomach, had a hich temp and my skin was completely red and broke out in hives. not fun at all.
sorry for writing a fucking book on this but it scares me when people just pop this stuff with out investigating the dangers of additional active ingredients and doesage.
Have fun. Be safe