Hi guys, I am playing Khan wars and I am looking for any other strategy game, what you will recommend me?

I used to play a lot of Forge of Empires, which is a very good browser strategy game. You play through the ages, as you gain new technologies, acquire larger and stronger armies that can be trained as various different unit types (i.e. infantry, bowmen, artillery etc), and as you progress through time, your units will become stronger. There is a very good guild system, which allows you to become 'teamed' with other players from around the world, and chat with them for good advice/ time passing, as well as trade with players around the world, so that you can gain valuable resources that are not able to be efficiently produced in your world and give resources that are able to be produced in massive amounts in your world, but not other peoples. A very interesting story introduces you to new characters along your journey.

What are your criteria for best?

I doubt that there is a really good one out there. Pretty much all browser games are mediocre at best where you have to

Wait to play, or pay to play

I'm trying out Forge of Empires right now, and I'm quite surprised to find that I'm enjoying it. It's something completely different. I don't want to pay for the ingame currency, and it doesn't look like I have to. Instead I'm giving my city orders and then check back several hours later, or even a day later, to receive a substantial amount of produced resources. In between I make time to build newly unlocked buildings, re-arrange buildings for space efficiency (akin to anno), complete quests, train units, attack/retaliate/interact with neighbour cities, do research and fight a few battles if needed.
The idea that periodically over the span of several months I'll grow a small city from the stone age through to a massive one in some futuristic age, small increments at time, is appealing to me. Perhaps it's just the novelty of it atm, and it might wear off eventually. But for now I'm pretty fascinated by it.