If your USB-C laptop won't charge it's likely because you're trying to use a USB charger incapable of delivering the required amount of power. A standard USB charger, such as that for your phone or tablet, won't do the job; instead you need a USB-C PD (Power Delivery) charger, which can deliver up to 100W.
So far so straightforward, although that 'up to' 100W can really cause some headaches. Some laptops, such as the USB-C MacBook, can get by on 30W. Other brands might require 45- or even 65W.
Before you choose any of the laptop chargers listed below, you need to find out one piece of information: how much power is required to charge your laptop?
That information might be found on the charger that came with your laptop, or on the manufacturer's product page. You're looking for a figure in Watts, although it may be expressed in Volts and Amps. If so, simply multiply these two numbers to get the figure you need. For example, a laptop that requires 12V/2A to charge will need a 24W USB-C PD charger (12x2=24).
Once you know what power rating you're looking for, finding a USB-C PD charger for your laptop is easy. Sometimes it can pay to get one a little faster than you need - it may be more expensive, but you'll be pleased you bought it if you later decide to upgrade your laptop.
Then all you really need to decide is how much you want to spend, and whether you just want a single USB output or multiple ports for charging all your various USB devices at once.
Also see: Best laptop power banks
Best Laptop Chargers With USB-C PD
1. Mackertop 65W USB-C PD Charger
If you want to charge only one device and your primary concern is power, and lots of it, this Mackertop charger with a single 65W USB-C PD output is among the highest-output chargers you'll find, and it comes at an amazing price.
The plug is built directly into the power brick, which means no unsightly cable mess. US customers will be able to fold the two prongs back against the body for easier transport, while in the UK you simply need to slide the provided adaptor over those prongs.
2. Apple 87W USB-C Power Adaptor
The price of this Apple USB-C PD charger is somewhat frightening, but we can't ignore the colossal 87W USB-C PD output it offers. That's insane.
It's probably also overkill for what you need, so check how much power your laptop can actually accept before you buy.
3. RavPower 60W 5-Port USB Wall Charger
RavPower is a big name in the charging world, and its USB-C PD charger has an additional four outputs - much like the below example from Anker. This one has a higher 45W USB-C PD output, however, with an additional 15W reserved for those extra iSmart 2.0 ports.
Though they can't all run at 12W at once, if you've only one extra device to charge you'll find the RavPower is a very quick tool for the job.
4. Anker PowerPort+ 5 USB-C
Anker is one of the biggest names in charging tech, and its PowerPort+ combines a 30W USB-C PD output with four full-size fast-charging USB ports for your other USB devices. These can each run at up to 12W, with a maximum of 30W output shared between the four. (That's in addition to the 30W PD output.)
The Anker is convenient for charging multiple devices, but if your priority is to charge a USB-C laptop then you should check first and foremost that 30W is enough to meet its requirements.