It's dangerous to dismiss a request as not interesting based on something as low-resolution as a response code. A 200 response in /admin/ from an unknown IP address is interesting.
In addition to the codes you have listed as interesting, 400 responses can be interesting (they are caused by Slowloris for instance and they are also caused by attackers manually crafting HTTP requests and getting the protocol wrong.)
401 responses can be interesting as they are generated by HTTP authentication (often called htaccess authentication). Lots of these can indicate a brute force attack.
In fact, I would say that everything in the 400 range is interesting. A full list of response codes can be found here.
But what you asked about was which ones are not interesting. For this, I would tentatively suggest the entire 300 range with the caveat that anything unusual is interesting. In practice, this means that 301, 302 and 304 are probably not interesting. 302 responses are often the result of form submissions and will be caused a lot by comment spammers so whether you consider this interesting or not is an individual decision.
The unusual keyword is probably more useful here than any particular response code list. This applies to every field in the logs. Unusual request methods such as PUT or CONNECT are very interesting, even if they return one of the non-interesting response codes.
Once you have found an unusual request that warrants further investigation, the next thing you should do is grab every request that the same IP address made, even if you would normally ignore them as being not interesting due to their response codes.
A series of 401s followed by a 200 could an indication that the attacker finally guessed the password correctly and got the admin page. If you ignore the 200 responses you might assume that it was an unsuccessful brute force attack.
After seeing a successful attack like the one above, you would then be interested in the URLs of every request the same IP address made rather than the response codes.