I don’t think there is such a thing as “Best” when it comes to poker sites. There are so many variables that need to be considered before your question can even begin to be answered. You haven’t even told us what type of poker you play. Texas Hold-em? Omaha? 7 Card Stud? Etc. Do you prefer playing in multi-table tournaments? Ring games? S&G’s? Etc. What kinds of players do you prefer to play with? Aggressive? Loose? Tight? What type of player are you? Do you prefer local players? Or International players? Friendly players? Little old ladies? (Careful or they will take ur $$$) Are you a high stakes player? Low Stakes? Play Money? Limit? No limit? Do you prefer Freerolls? Maybe you want to play for a free seat at WSOP. Are bonuses important to you? One of my favorite sites (World Poker Exchange) offers NO bonuses at all…but it also has NO rake. Is software important to you? One of my favorite sites for tournament play (Doyles Room) has the worse software out there (in my opinion). What time of day will you be playing? One of my favorite sites (Action gaming) has hardly any players playing at 3am, but their software is second to none and the players are very friendly during daytime hours. Also, some sites cater to 10 person tables. Some to 9 person tables. Some to 6 person tables. Maybe you prefer Head’s-Up (2 person) games.
You don’t need to know the answers to all of these questions yet, but at least give us a better profile of yourself as a poker player so that we can better help you.
Welcome to the site.