Stanley 1-95-611 Fatmax Tool Backpack with seprate compartments for tools and other items such as laptops £33.40 @ Amazon

Heat. Lowest I've seen it in some time. Currently £40 at Screwfix.
It's a great all-around engineer/technician bag. The removable insert lets you pack in a lot of tools while also keeping them accessible.

I have one of these (IT Engineer) Must be about 8 years old now. Great piece of kit. The plastic re-enforced bottom makes it sit upright, and it has a padded slot for a laptop and removable tool pouches. I'll definielty be getting another one if my current one falls by the wayside - But no sign of that yet. Highly Recommended.

I am a gas heating engineer and this has to be the best tool storage purpose I've made. No more carrying around a heavy tool box and another bag for an analyser etc. I use this bag every day, Its perfect for what I need and use it for, I can store store an arrange of tools, screwdrivers, grips, wrenches etc and have space for my analyser, probes, multimeter and manometer etc I and still have bags of room.
Simply throw it on your back and I have two free hands to carry boiler parts, my bucket or whatever I may need.
I've had mine for over a year now and nothing has broken, become distorted or anything of the sort, I can't recommend the bag enough it's fantastic quality and for this price is a must have! (edited)

I actually use this one for my job. It’s much easier to carry/organise then the usual 1 shoulder strap ones.

All the lads on site have these (sparks) , I opted for the veto tech pack , I have to admit that I'm feeling a bit stupid hahaThese do seem to last well and for £30 odd you can't complain at all.
As others said ,.they are perfect for site workers who can't park near to the workplace .
The only downside is you can't fit everything you need in a backpack and carrying another bag is awkward , I need a solution to carry in my power tools as all my hand tools live in the rucksack

now £39.99