The production of high brightness electron beams has been key to the success of the X-ray free-electron laser (XFEL) as the new frontier in X-ray sources. The past two decades have seen the commissioning of numerous XFEL facilities, which quickly surpassed Synchrotron light sources to become the most brilliant X-ray sources. Such facilities have, so far, heavily relied on room temperature S-band RF photoguns to produce the high brightness electron bunches required for lasing, however such photoguns are reaching their peak performance limit and new methods must be investigated to continue to increase the brightness of these facilities. This talk will begin with a review of the design and performance of several electron guns currently operational in XFELs. Following will be a discussion of current efforts in continuing to increase this peak brightness including moving to cold cathode schemes and the use of very high gradients on the cathode. Finally we will describe ongoing activities at PSI to develop the next generation of high gradient RF photoguns for increased peak brightness.