A few observations:
The glass can make or break a cocktail as can the type of ice used.
Take your time make it right and enjoy-this is not the time for power drinking.
Great Manhattan Recipe above-although I would cut back on the cherry juice as I'm not that much into sweetness-the cherry does it for me. I remember fighting with my brothers over who got the cherry in my grandparent's drink!
I always liked a small twist of lemon on a bourbon & water.
I always like a dash of Angourstia bitters in my gin and tonic.
GOOD vermouth is a must in any drink that uses it.
Use Cointreau NOT triple Sec in your Margaritas.
Use real ingredients and NOT mixes whenever possible. Mixes have wayyyyy too much sugar/high fructose corn syrup.
It is amazing how a drink can hold it's temperature when properly shaken and poured into the correct glass without adding an ice cube.
Sometimes simple is better-as in a nice 6oz coctail glass with one cube of hard ice with a dollop of very high shelf Bourbon/scotch/vodka/gin/rum or any other flamable liquid you feel like drinking that evening.
Finally, day drinking is best left to experts

Alcohol is a fine adult pleasure-but like anything else it can turn on ya and grab ya by the balls.
And now for my margarita reciepe
2oz GOOD tequila
1oz Cointreau
1oz fresh squeezed lime juice (Mexican limes if you have them)
Shake and enjoy over rocks-with or without salt as the case may be