I love the Bat/Cat relationship. In Hush is where there romance really started out… I think. Apart from the hush storyline (Heart of Hush and all that included) are there any good Batman/ Catwoman issues. I’m looking for a relationship between them or where a decent amount of flirting takes place.
 
Or any good Catwoman/ Others I know in the first Catwoman series there was flirting with the trickster & a relationship with a cop who turned out to be a villian his name escapes me at the moment.

Thanks for the help.

You should check out Batman Incorporated that just started up last month if you're not already.  The next 2 issues will have more Bat/Cat in it I believe and there will be more later in the year after that too I think.

You cannot go without reading: 
Batman Year One (trade) 
Batman: the long Halloween (trade) 
Batman: Dark Victory (trade) 
  
The Bat/Cat relationship isn't the focus of any of these stories but it's awesome to watch it develop, albeit very slowly (they still don't know the other's identity, etc, & really are only "together" in a sense as Selina & Bruce)

There was also a flourishing batcat relationship pre-crisis between Batman 300-400. In some cases she appeared just as Selina Kyle, reformed thief who was dating Bruce Wayne. There was an issue called Night on the Town (Batman #392) where they go on a date as Batman/Catwoman but keep getting interrupted by crime. It's hilarious.

Ooh chips, I'll have to find that one & check it out haha. 
& the first few Batman Inc's feature Catwoman also.