Are there any domain suffixes that will lead you to a website even if the domain you are typing in doesn't exist? I know for a short while Network Solutions tried doing this for all non-existent .com's, which caused a huge controversy.

Are there any today that still does this?

By domain suffixes you mean TLDs (.com, .net, .org etc.,), then it depends on their respective registries.

I believe godaddy and other registries filed a case and ICANN ruled against Verisign (NetSol).

But I've seen some ccTLDs doing what Verisign does but I think they are allowed because its not generic.

But I dont believe any gTLDs registries do this at the moment, at least I am not aware of one.

Any particular reason you are concerned?

Cameroon (.cm) wildcards their DNS for non-existent .cm domain names.