I just want to show how many user viewed a post (says 12 views) and a widget for top viewed blog list in the sidebar any plugin for the above concepts
http://wordpress.org/extend/plugins/wordpresscom-popular-posts/ is the one I use. it offers template tags to hardcode into yur theme if you like, or shortcode for pages/posts, or a widget
So it seems to do everything you want
It is dependent upon the wordpress.com stats plugin, or the jetpack plugin however to function. I like the wp.com ststs plugin personally
This one - http://wordpress.org/extend/plugins/wp-postviews/ - offers post/page views and also template functions and widgets to show the most viewed posts/pages.