Kids' favourite Lego is often best bought by the kilo or pound on e-Bay. The essentials are a large flat base and plenty of basic bricks. Even if you're buying everything new it makes sense to purchase bulk packs in standard sizes, because much of the fun comes from using your own imagination to design castles, starships, motorboats and more.

LEGO Basic Bricks #6177

Playing Lego using your own designs is also an ideal way for parents to share an open-ended activity with their kids. It's not too noisy, rules and instructions don't get in the way of imaginative play and you can make just about anything with enough bricks.

LEGO Star Wars Trifighter Droid (8086)

It's tempting to go for some of the large themed packs of Lego, which cover a wide range of popular themes, including Atlantis, Prince of Persia and Star Wars. These packs are beautifully presented and buying into a theme like Batman can sometimes make all the difference to a kid who usually prefers videogames.

Lego Make & Create Café Corner

There are, however, a few sticking points with the boxed sets. To start with they tend to be quite expensive and usually involve setting players the fixed task of constructing the model shown on the box. Kids and parents can then find that imaginative fun turns into following a lengthy set of instructions. There's some compensation in achieving, and playing with, the end result but it's generally best to avoid being too overambitious first time round.

LEGO Star Wars Clone Walker Battle Pack (8014)

Apart from the basic cost, Lego's themed packs can also present a problem in terms of how to get more use out the bricks. Once you've finished building and playing with a themed pack you've to decide whether to set the pack aside or mix it into your overall collection. The first option means getting less use out of the bricks as part of your overall collection, while the second option makes it almost impossible to find all the parts from one set amongst everything else. In addition, there are often a lot of specially shaped bricks in theme packs, which may not be of much use when making your own Lego models from scratch.

LEGO Racers Ferrari 430 Spider

As a result, it seems best to start with smaller themed packs unless you definitely have a kid who's a real enthusiast. In that case a $100 - $150 pack is an ideal introduction to the world of more expensive but rewarding 'Luxury Lego'.

Luxury Lego

Lego has helped to entertain and challenge millions of young kids between the ages of about 3 and 7. Many kids will make little use of Lego thereafter, as a vast range of quick and easy alternatives take up most of their time.

However, for some kids the large, themed Lego sets are of most value for creating settings that support imaginative play and roleplaying. These kids will be more than happy to construct an entire Harry Potter's castle, then keep it as it is for months while they play games based around the castle and its characters.

The chances are that such kids will welcome 'Luxury Lego' with open arms. 'Luxury Lego' basically describes specialist sets of Lego, which are sometimes expensive and often little short of spectacular when put together.

LEGO® Creator Taj Mahal (10189)

Perhaps the most remarkable of the currently available 'Luxury Lego' packs is the $299 Taj Mahal model. The commitment needed to complete the 5,900+ piece design is almost as great as the cost but the end result is remarkable.

LEGO Mindstorms NXT 2.0 (8547)

Many enthusiasts might get better value out of the Lego Mindstorms series, which takes traditional brick building Lego into the world of electronics and robotics. The Mindstorm packs equip Lego to offer a thorough grounding in designing and controlling robots and can, potentially, improve kids' and students' employability in areas such as programming and engineering. At $199 the Lego Mindstorms NXT 2.0 is the current robot of choice.

Lego Architecture Series Set Of 6

A similar 'real world' approach underpins the design of Lego's Architectural Series. These models offer masterclasses in the design and construction of some of the world's leading buildings. There's the Sears Tower, the Empire State Building, the John Hancock Building, Seattle's Space Needle, the Guggenheim Museum and Frank Lloyd Wright's Fallingwater to choose from. Though you can order the complete set.

LEGO Architecture Fallingwater (21005)

The pick of the Architectural Series is Lego's take on Fallingwater. There could be few better ways to explore and 'get inside' the architecture of this inspirational building than by visualising and realising its construction as you put the pack together. The Fallingwater design is, perhaps, too 'industrial' to entertain youngsters but there's a lot to learn for teenagers and students looking at careers as architects and engineers.