There's Kakaku.com[1] in Japanese Internet for all consumer electronics, Minkara for cars, bookmeter.com for books, and 5ch.net as fallback. It's surprising that there's only Goodreads on English Internet that everyone have heard of...

1: https://review.kakaku.com/review/K0001682323/ | https://review-kakaku-com.translate.goog/review/K0001682323/...