UB40 moved away from roots reggae around the mid 80's after forming in '79. They started to bring out covers such as Red, Red Wine and IMO went downhill, although it was still good but nowhere as brilliant as before.
I think the only tracks that made the charts from that early period was King, Food For Thought & One in Ten and they weren't even the best.
I won't list them all, but here's a track called Madam Medusa about a bitch called Thatcher. Over twelve minutes of pure quality roots reggae.