I chose AppGuard because it's capable of blocking more threats. AppGuard does more to mitigate exploits than an ordinary whitelisting AE. It has memory, registry, and file protection. It can also block malicious dlls, scripts, .tmp, etc. I think it's memory protection is it's most unique feature though. AppGuard does have it's short comings though. AG is lacking hash functionality. If AG also had hashing it would allow greater control over what is allowed, and denied. It would increase usability for one. AG also will allow any signed file to execute in the user-space with "limited rights" in Medium Protection Mode. I recommend always operating in Locked Down Mode when surfing risky sites, but popular well known sites can become infected as well so keep that in mind. AG does do a good job sandboxing crypto malware, but my philosophy is never allow a malicious file to execute to begin with so you don't have to worry about containment.
I also really like ERP because of it's vulnerable process feature. The vulnerable process features gives sort of a HIPS control of vulnerable processes by giving the user control of their command lines. That is something AppGuard does not have. ERP also has MD5 hashing of course, but I would prefer it be upgraded to SHA-256. I have found that ERP also runs extremely smooth on all my systems. ERP is an amazing application, but I think the developer is more than capable of making it an even better application for power-users. The developer already has other applications that can block any executable file, including drivers. I think that functionality could be combined into ERP to provide even better security against all categories of threats.
I guess most of the users here have already heard of Smart Object Blocker by NoVirus Thanks. It could turn into the next wet dream for security experts, and enthusiast. All rules currently have to be written by the user in a ini file, but that could change later on. I'm currently learning how to set it up myself, but I think i'm really going to like it. It currently has a very simplistic UI that only give access to settings, and rules which the user has to configure for themselfs. Well, there's also access to the log file in UI, and some directions on how write the rules/policy. I'm learning as I go along myself.
Bouncer should have been listed in this poll. There's a lot of great features coming in the near future with Bouncer. It is implementing memory protection, hashing, command line control, and several other features that I don't know the specifics to. Excubits, the developer of Bouncer already has all the features listed above in individual applications except for the memory protection, but they have not been combined into one product yet. The memory protection feature is still being developed AFAIK, but I don't know what stage of development it is in. According to the developers blog it could be complete, or almost complete. I'm not really sure. The developer of Bouncer does all the mitigations within the kernel, and Bouncer is going to be very similar to AppGuard in some regards. I'm looking forward to testing Bouncer with the combined functionality.