This is a really great base to start with for building an authority review site. It's been registered for 16 years. As you will find, any good name for a review site has long been taken. "Top Ten" lists are very popular and this name gives you a great brand to start building with. People know right away what they are getting when they see your domain name and it's an easy name for them to remember to come back to.
As you might notice, TopTenReviews.com is a huge review authority site. A 1000 alexa site, it's one of the most trafficked sites on the net. This gives you a look at what someone else has done with the plural of this name.
Similar name sales:
realreviews.com 25,000 USD 2014-10-15 Sedo
topreview.com 10,000 USD 2015-03-02 Flippa
toptenvideos.com 7,888 USD 2015-02-19 Flippa
ezreviews.com 5,000 USD 2013-02-27 Sedo
consumerreviews.org 3,388 USD 2008-08-19 Afternic
amazingreviews.com 3,200 USD 2015-04-04 Flippa
toptenthings.com 3,188 USD 2009-12-09 Afternic
totalreviews.com 2,993 USD 2008-12-02 Afternic
toptengifts.com 2,495 USD 2012-05-09 Afternic
toptender.com 1,168 USD 2011-07-12 Sedo
topfives.com 2,000 USD 2009-06-16 Afternic
As you can see, any brandable review domain fetches a good price at auction.