Japanese publisher Spike, who release many western games in Japan, recently asked over 6,000 Japanese gamers if they’d rather play Western games with subtitles or dubbing.
The “winner” was subtitles with 49% of the vote, followed by 47% with dubbing. 4% just simply didn’t care. Or words to that effect. The breakdown for specific genres though is a little more mixed – 59% percent want dubbing in first person shooters but for RPGs only 45% percent want dubbing.
If you read Japanese and give two hoots, there’s a dedicated website of the findings.