I'm probably not going to be able to answer the question, but those that will, probably need to know your budget.
I work in a charity shop and we get a lot of soundbars that are small and compact and they all sound awful to my ears. They're often very cheap sub £50-new unbranded/chinese speakers that sound tinny, lacklustre and pathetic. It's a bit like the tripod trinity of light vs sturdy vs cheap. With speakers it's size vs sound quality vs cheap. Pick any two.
Oh - and edit to add - what's the connectivity to your PC currently? Bluetooth? the old 3.5mm speaker-out? digital-out? phono leads? Do you have a connectivity preference? (i.e. not bluetooth?)