Chromecast and other streaming protocols send data over your local network, but that's a problem when you're using a VPN. Those devices are looking for streaming data from phones and computers on the same network, not from a distant VPN server. Likewise, smart home devices may be gathering lots of data about you and your home that you'd rather not have intercepted. Unfortunately, these devices simply cannot run VPNs. The solution for both problems is to move the security up a level by installing a VPN on your router. This encrypts data as it leaves your safe home network for the wild web. Information sent within your network will be available, and any smart devices connected to your network will enjoy a secured connection.
Hardware-based VPNs tend to be less vulnerable than software implementations because their chip-based OSs are more lightweight (i.e., they have fewer features to exploit than general-purpose OSs). Also, because they don't sit on everyone's desktop, they're less used and understood, although exploits on them aren't unheard of. For example, security researchers recently discovered several security holes in Cisco's VPN concentrators. Make sure you subscribe to your VPN vendor's security update mailing list and promptly apply all security patches.
Cost - VPNs aren't too pricey, but they vary from vendor to vendor. If your main concern is price, then go with something inexpensive, or free - like Spotflux Premium VPN or AnchorFree HotSpot Shield Elite. By all means, try a free server but they do have a few drawbacks since they attract a lot of users. Free servers are often slower, and since most are ad-supported, they place adverts on the online pages you access. Others can even limit the speed of your connection, as well as your online time or amount of data transferred.
OpenVPN: OpenVPN is very secure, open-source and widely used. Most VPN services support it, but except for Chrome OS and Linux, few operating systems do. This protocol can be used in either TCP (web) or UDP (streaming) mode; the latter is sloppier but faster. You'll need either the VPN service's client software or one of the many free alternatives. Either way, you'll still need to pay for the VPN service.
They even offer the most generous simultaneous connection count, with six simultaneous connections through their network, where everyone else offers five or fewer. NordVPN's network isn't as large as some of their competitors, so if you're trying to obfuscate your tracks, you might want a company with more servers. Otherwise, this company is clearly providing a winning offering.