For all you into reverse engineering and don’t want to shell out for IDA Pro or want something a little newer than Olidebug, there is an open source, actively developed and supported debugger conveniently enough named x64debug. I have used it and find it to have all the functionality you could want in a debugger.
Along the same lines as my previous post about alternatives, the NSA has released one of their custom built tools to the public. I haven’t tried it yet, but am planning to in the near future. If you are interested go check out GHIDRA 9.0. Happy bug hunting!