Böker classic, optima, and boy scout knife are all nice. Similar to a Buck 110/112
Cold Steel models are all top quality, and the triad lock is a mid lockback design; and the xhp steel models can be had in the same ballpark as a 110, so better Steel then the 420hc; their Mackinac and Lone Star are more traditional styled with TriAd locks, (though aus8, not xhp, however CS's aus8 is as good as it comes) so definitely stronger locking mechanism and with a clip, and equal if not better Steel.
Case Lockback folders are similar to Buck as well in terms of overall build. Not a Buck 110/112, but similar, and in most cases cheaper, and their trusharp (420hc) is akin to Buck's.