There are 220 matches for the word "count" in this thread, but not a single Count interaction. Time to change that!
Count/Crossroads or Count/Shepherd
Count is amazing for those strategies where you build your drawing engine from green cards:
- efficiently trash away your starting Coppers
- gain Duchies to fuel your engine and maintain a lead
- kickstart your next turn by putting a Crossroads/Shepherd on top of your deck!
Count is actually not that great at trashing away your starting coppers. An average hand is CCEXCount where X is one of your openers or your other T3/4 buy. Assuming you want to keep both E and X that means that Count kills 2 coppers per play as a terminal. Which is on par with all the other 2 copper trashers ... but is a terminal $5. Worse, you will quickly have fewer turns where you can safely trash 2 coppers and eventually you will have several coppers that Count simply cannot eliminate. When you have other copper trashing you normally want it for a Green/Count engine.
Don't get me wrong, Count is a trasher of coppers, but when you actively want the estates his trashing is even slower than normal. It is something like four shuffles to get down to 2 coppers which is about what you can manage with Moneylender.
That being said, even inefficiently trashing coppers is enough to enable things like Shepherd or Xroads, particularly as Count can smooth out early cash flow, top deck whiffs, and then gain duchies.
For Count combos I have always loved Tomb. Pretty much any engine setup can turn Count into an unbounded golden engine with Tomb. Count/Beggar/Village/Tomb? Well that's 12 VP/turn. Lost arts/Count/Silk Merchant? Not too hard to hit 7 VP/turn. Even something simple like Tr/Count can churn 3VP/turn or more and still let you buy cards.