My favorite anytime boating is Captain Morgan and cola. "Let the Captain do the driving!" I always say.

It's your preference when mixing with the juices. 24/7 drinks I remember seeing are: (one or more)
OJ
fruit punch
grapefruit
lemonade
cranberry punch
tea (I love rum & tea)
coffee (w/whiskey or Kalhua or Baileys)

Vodka and Rum pretty much mix with anything. I perfer rum as all the cruises I go on are Carribean. (Christopher Columbus took sugar cane to the Caribbean, rest is history.)

Beginning of cruise, tip your cabin steward and tell him/her you like ice refilled in your room constantly. You'll have plenty. I also put one of my "beer buckets" in the cabin and have that one filled too.

There is about 15 drinks in a liter of alcohol. It's about $5 a mixed drink (or beer.) I bring a 1.75 liter just for myself (usually Capt,. Morgan.) That's 26 drinks or at least $130 worth of drinks for a $35 dollar bottle. Don't forget the mandatory 15% gratuity added to each drink order.

Kewl cruise related website. LOTS of info:
http://cruiseclues.com/

Just booked another cruise for APR 2010 with friends coming! Woot!