Congrats on getting your PAL, and your first choice of shotgun. Depending where you hunt, you'll be able to use it for fowl, deer, moose, bear, turkey, pheasant, and just about anything else you can think of.
I've got a Stoeger P350, and love it. A lot of people say it has jamming problems, but I've fired and fired it, and haven't had one problem. My next shottie will either be a Benelli Supernova or Super Sport, with a 28" barrel.
If you decide to get a Marlin down the road, you can't go wrong with their lever action, in a 30-30 caliber. I've got one and love it for bush hunting; I've got mine set up with peep sights. For open field hunting, I've got my bolt action Browning A-bolt 30-06, and I love everything about it. The weight, action, feel of the trigger; the only thing that annoyed me about it was the stupid gold colored trigger, which I immediately corected. If the cost of ammo wasn't so pricey, I'd be firing it at the range every day I could. After that, I'd say my two Lee Enfield 303s are fun as well. One has the old iron sights, the other has peep sights. I love them, and have a blast everytime I take them to the range. They're typically the rifles I use to introduce newbies to firing. I'm sure you'll get into the hobby and find your own favorites; just figured I'd share some of mine.