If you’re Windows, I’d go with OneDrive as it’s built into Windows, syncs with other Windows devices and services, also on iOS and Android. Reliable in my experience.
You already get some storage included with Windows (if you’re on Win 8 or 10), and can get little bonus amounts from a few offers.
Use Office? Get an Office 365 sub and you get 1TB of storage. 365 Personal is £60 a year or £6 a month. Gets you Office sub on 1 PC plus mobile/tablet. Home version £80 or £8 a month and gets you 5 subs for the house (each get 1TB).
Even if you don’t use Office itself, £60 for 1TB is not bad, especially as you can stick what you like on it (Google’s unlimited photo storage limits the resolution, non-raw files etc. With OneDrive you can also dump your music collection in there and it’s instantly available in their Groove app to stream).
DropBox – don’t reuse a password you use elsewhere, and turn on 2 factor authentication. They got hacked.
Google Drive is a bit of a faff to get photos to sync as a normal folder and Windows to recognise it, for some reason. By default Google assume Android and their own photo app, so don’t sync the photos to Windows.