In reply to JamButty:
reverso style guide plate will be the most versatile thing you can buy, behaves exactly like your sprung sticht plate but can be turned into an auto locking device for seconds, be used as an ascender or as part of a pulley system. Definitely very useful if it ever comes to self rescue...
Other option could be a gri gri, but it would take a bit of practice to get smooth with as slightly different style of belaying to a standard sticht plate. Useful if you do alot of sport or expect to get belayed by novices.
Bar that, atc or bug are simple modern updates on the classic sticht plate.