I use
www.gotomeeting.com and
Raindance
GoToMeeting I use for the intimate under 10 people webinars and there is a monthly fee – check out the best options for you.
Raindance I use when unlimited participants is the format – you are billed only when you use it with a per minute/per person rate. Check out best option for you.
Both are great and I was particularly impressed with the
customer service at Raindance.
I hope this helps!