I'm from NW England, and where I grew up the standard informal greeting has always been Hiya. The 'h' is usually dropped, so it sounds more like 'eye-yuh'.
One slightly unusual thing about the 'Hiya' of this dialect is the way that it is pronounced. Because of the local accent, speakers will often stretch the sounds out and deliver the greeting with a particular rise in intonation that makes it sound like an expression of surprise.
Many a visitor from London or elsewhere in the English-speaking world has been confused by this. You might walk into a random petrol station or shop in or around Manchester and be greeted with an 'Eye-yuh!' that sounds like "My god! It's you! I can't believe it. It's so nice to see you after all these years!". Local Manchester people probably wonder why their friendly greeting is often met with blank looks of confusion and embarrassment.