Angry Birds has managed to take over most of the world ever since Rovio launched it onto Apple's App Store back in December 2009.

The Angry Birds franchise now spans a whole bunch of mobile games, boardgames, animated TV episodes, and merchandise. You can even find the miffed avians on the side of an F1 helmet.

Merchandise related to video games has always been a tad hit and miss, so we've taken the liberty of selecting five items from Rovio's online store that we think are worth your attention.

We've also picked five pieces we think you should stay away from. We're fair like that, you see.

The good

Blue Bird keychain
Buy for €8.99

Okay, so the Blue Bird keychain isn't the most daring piece of Angry Birds merchandise you could stick in your virtual basket, but - you have to concede - the little blighter would look pretty suave dangling around below your keys.

If you aren't really a fan of the Blue Bird, fear not: the majority of Rovio's miffed avians are available in keychain form. We kind of like the red one, too.

Angry Birds: Knock on Wood boardgame
Buy for £15.98

If you're unfamiliar with the Angry Birds: Knock on Wood boardgame, it's basically a real-world physical version of that feather-flinging game you were playing on your smartphone 15 minutes ago.

So, you'll find yourself launching little plastic birdies out of a little plastic catapult in order to obliterate the little plastic blocks that protect the game's little plastic piggies. That's a lot of plastic.

Check out our review of the game to see it in action.

Plush toys
Buy for €32.99

Admit it, they're ruddy cute. You can do a lot with these soft plush toys. You can sit them on your desk next to your computer monitor, proudly display them next to your collection of physical games, and throw them at your naughty kids, for example.

There are plenty of plush toys to choose from in Rovio's online store, so we suggest you have a good look before making a choice. You can buy them in packs of three or purchase your favourite feathered flier on his lonesome.

Bad Piggies' Egg Recipes cookbook
Buy for €19.99

This colourful cookbook features 96 pages of adventurous recipes to spruce up those three eggs you've had sitting at the back of your fridge since this time last year. Yes, every recipe in this book revolves around eggs.

If the only egg recipes you can think of are called "fried", "boiled", "poached", and "scrambled", you should probably give this book a once-over.

Red Bird iPhone 4 case
Buy for €24.99

iPhone's aren't cheap, and they're definitely not as durable as Rovio's line-up of birdies. What we're trying to (subtly) tell you, then, is that a protective case is probably a good idea.

If you like protecting your gadgets and you absolutely love Angry Birds, one of Rovio's cases could float your boat. If you're not a fan of the Red Bird, though, you can also grab cases featuring the Black Bird and the Yellow Bird.

The bad

Red Bird felt iPad case
Buy for €49.99

As much as we like cases for our gadgets (and Angry Birds), you sometimes reach a point in your life where you just have to turn around and say 'no'. This case marks that moment.

As you can see from the cropped image above, Rovio has basically taken its Red Bird, zoomed in on its ugly mug, and decided to reproduce the image. In felt. It's kind of scary.

Playing cards
Buy for €9.99

There's a ton of fun to be had with a pack of playing cards. Snap, for one thing.

In all honesty, though, you can probably grab a deck from your local supermarket for next to nothing and pick up Angry Birds Space for your iPhone or Android-powered device for the same price as this Angry Birds-emblazoned pack.

Green Pig plush backpack
Buy for €36.99

Pigs aren't the most handsome of creatures to walk this earth, so why would you want to pack one full of sandwiches, books, and pencils, and strap it to your back?

Nope, we don't know, either.

Magnetic playset
Buy for €13.99

Admittedly, these magnetic playthings look kind of fun. Hey, we said, "kind of". Basically, you can create your very own Angry Birds stages using magnetic wooden blocks, magnetic piggies, and magnetic birds.

It just seems a little silly when - for around the same price - you can pick up an actual Angry Birds game for your smartphone and smash scenery to bits without having to simulate it yourself.

Red Bird novelty hat
Buy for €29.99

Oh dear. This is all getting rather ludicrous now. You have to be a serious (and we mean serious) fan of Rovio's physics-based franchise to even consider wearing the above article of clothing.

A nice T-shirt, yes. This hat, no. Just no.