Ramsay, I have 5 CDs from B'z and quite like them, their style is diverse and ranges from Pop over Rock into Metal with lots of other elements (traditional Japanese, sometimes Country, Classical music etc...) included. Their music is never boring.

I would recommend their album "Loose" from 1995, which I think is one of the easiest "accessible" for Non-Japanese people

Wanted to give you some YT-links, but my favorites are in Japanese language so what can I do.... ?!? ( CD "Loose" track 4 - incredible!)
Really enjoy the singer Koshi Inaba who puts in this special kind of melancholy in his singing.

PS: Can remember an interview with Jack Blades for TMG1 where he said to me when he walks the street with Tak Matsumoto in Japan he thinks he is with Elvis or the Beatles in their heyday, such are the reactions...