Lego is a great toy for 5 year old boys. It keeps them occupied for hours and has so many educational benefits too. It's fantastic for facilitating imaginative and creative play. They can build their own constructions (houses, towers, robots, boats, animals, dinosaurs, trucks, windmills - the imagination is the limit and play with them for ages afterwards. There are also some great lego sets (fire engines, planes and more - see the sets below). These help develop problem solving skills, concentration skills and give a good sense of achievement when completed too. Amazon.co.uk have some good existing deals on lego which make great gifts. The fire station below is reduced from to £61.99 to £35.94 , the plane was £35.99 and is now £24.95 and the helicopter from £9.99 to £6.69.
Lego Games
Lego games are great. First of all you have to build them, which is a great activity for 5 year old boys to do (maybe with a bit of adult help). My son loves Shave a Sheep. We had great fun building the sheep, wolf, and dice. My son really enjoyed playing it and wanted to play it again and again. It is quite a simple game but can get quite addictive. You can also change the rules around if you want to. Currently there is 25% off lego games on amazon.co.uk. Shave a Sheep has been reduced from £7.99 to £5.99.
More Construction Toys
You can currently save 38% off citiblocs on amazon.co.uk. This 100 piece high quality wooden block set has blocks which are all the same size. I've not had personal experience with citiblocs but it looks like the type of construction toy which will keep 5 year old boys occupied for hours. Build houses, towers, city blocks, offices, bridges, walls, farms -the imagination is the limit. Great to learn about gravity, weight, balance and stability.
Galt Connecta Sraws. These straws aren't on offer but they are extremely good value - especially considering the playing time that you get for spending £6.99. My son has played with his set of straws for hours constructing shapes, flowers, windmills, robots, space rockets and houses - again the imagination is the limit. You can get more and more complicated structures including helicopters, animals, dinosaurs and bikes.