I would definitely recommend Townsville, I have lived here 5 years after spending the first 5 years of my time in Oz in Sydney which I didn't like at all (I was a poor student - it would be great place to live if you have plenty of money). I have spent a lot of time in Cairns and also really like it there, to me the main advantage of Townsville is we are drier than Cairns - they can get rain that sets in for weeks on ends and we really don't get that much. Cairns is probably better placed for tourist stuff - closer to the reef, tablelands etc. etc. Townsville has everything you would need, 4 cinemas, lots of restaurants, pubs, parks, the strand, shopping centres - it is not the big city but then I like that. There are a lot of small towns in Australia that I wonder how on earth anyone lives there, they have one high street and thats about it - they would drive me nuts. But equally the big cities where you spend ages in the car getting to anywhere don't appeal either. Townsville is in the middle. In terms of good suburbs - avoid Kelso, Rasmussen, Condon as they are a little out of the way and there is a fair amount of housing commission. Mount Louisa, Douglas, Annandale, Mundingburra, Cranbrook and Aitkenvale, Hermit Park, Pimlico, Mysterton, Idalia, some parts of kirwan. I would highly highly recommend renting for a year before you buy anywhere as you really can't pick a location before you've lived here. I would also say that Townsville is a 2 year place - you need to give it 2 years of being not sure about the place and then you'll never want to leave! I am always happy to meet up with new arrivals, I met lovely poms through this forum 5 years ago and we're still friends today.
