It is true that you will probably find a freeroll at every poker room but there are some that stand out above the rest. If you want to be playing freerolls till they come out of your ears...
Amongst the exclusive freerolls at
pokerstars there's the hubble satelites to several round two's over the weekend. The 100K Privilege which has a $1000 pool and several times a day for which you get a 30 day ticket when some depositing conditions are met but you can also get a day pass for free from the VIP store if you are ChromeStar or above.
FullTilt has similar round 1 satellites to two weekly $250 Round 2 tournaments one giving TT (tournament tickets) and the other RGT(ring game tickets). They also have two $50 freerolls which you have to register for within the hour.
NetBet on iPoker is probably the best for freerolls they have several Instant Win tournaments that reward Twister tickets and then there are the free festival that are hourly $5 freerolls. They also have a free 5c 9 person SNG pays 3c to winner and 1c to 2nd and 3rd each, this is on demand but there is some unwritten monthly limit cap.
Everest also on iPoker has a step on demand SNG system they call Sashta, step 1 is a fixed limit 6 max sng freeroll capped at 4 per person per hour, the rest are all no limit, 2 places paid step 6 awards a $10 tournament token which gets you into some serious pricepool tournaments. In addition to Shasta they also have their own multi entry freerolls (3 max I think) which awards shasta step 2 (10c) tokens.
Betonline on Action Poker network has at least one freeroll per hour ranging from $25 to $300 pricepools.
Doxxbet I'm not sure exactly which network as they run on 2 networks but I could only ever play on one of them. They have many freerolls but they are either satellites or they pay you it points, which sound awesome I think you can win 2000 points which eventually translates to 20c and not likely to give you a
bankroll anytime soon.
nJoy!