probably the case has ventilation problems with rear exaust getting blocked or the cooler is not properly mounted. but if you are looking for good cooling, hyper 212 is good, even for medium oc with i5s, it will probably run those games @60-66 degrees. cheaper liquid coolings on the other hand are not exactly that cheap and neither they are as effective.
but before you do anything, do a little test: run realtemp before launching bf3/crysis and take a log. make sure the data is started to be recorded in the log and then play games with those temps for few minutes. then share that log file here, let us take a look.
Real Temp - CPU temperature monitoring