I am almost reluctant to post this set of links.
It's one of my 'guilty pleasures'.
This site is also where I got started coding html & css...and that lead to other coding.
You don't need an account to play the flash games...you only need one to get neopoints which is the currency in their virtual world.
I am only going to list a few of my fav ones:
Advert Attack (first time I played this I couldn't stop laughing...I used to send people that got spyware infections to play this as 'training')
Carnival of TerrorChemistry for BeginnersDeckswabberDestruct-o-match IIEscape to KreludorExtreme HerderGadgadsgameand my favorite:
Meepit Juice Break (those hamster-like creatures are just too cute when they die!)
There are tons more games on the site...and some are not flash but you need an account for those.
And some are ad sponsored games with a product theme, like popular American breakfast cereals.
This site used to be a HUGE time waster for me... at one time it was an obsession!