There isn’t one right answer to this question. Just like which music style is the best or which brand of chocolate is the sweetest. Clearly there’s a lot of opinions on these topics and all of them can be right. With autoresponders it’s pretty much the same, anyone can claim that a certain autoresponder is the best and they will be right in some way.
But you can try to compare autoresponders and one of the factors is the price, if you are looking for the cheapest solution then ListWire is the winner, it is totally free, but by being free it has its own limitations. One of them is that you can’t create single opt-in lists, it shows ads on your links and other stuff. You can definitely put up with that, if you don’t have the money to pay for a decent autoresponder, but if you are running a real business you will have to choose one that costs money.
Still, if you are going after a low price then ImnicaMail is a good choice, but again with a low price comes the problems. First is the bad deliverability, then the often technical issues and some other stuff. By the way I stopped using Imnica like 4 months ago, I just logged in and they still haven’t noticed I stopped paying.
Then there’s Aweber and GetResponse, the industry leading autoresponders they are more expensive than Imnica, but they have everything that you need and the services are professional. When choosing one or another you should think about which autoresponders interface you like the most, you can try them out with their trial offers.
I use both of them, but I like Aweber’s interface a lot more, in GetResponse I have a hard time writing an email or managing my web forms, but Aweber does cost $4 more per month. So, for me it’s price over convenience.
When you start playing with the big boys, when you have a list in the 6 figures, using GetResponse or Aweber might become cost inefficient and you might consider using InfusionSoft which isn’t just an autoresponder, but a whole marketing package. From its price you can tell that it isn’t for people who are just getting started, but at some part of your business you might want to consider it.
Now, I haven’t even talked about self hosted autoresponders, but I don’t think you would want to go through that process. So, there really isn’t one best autoresponder for everyone, but if I would have to pick, I would choose Aweber, mostly because of its interface.