I think you're asking for the next better option over the Fenix, rather than the next - second - best option. For a $37 delivered 1W, R-bin, 1AA, HA, UCL, LED light, I don't know that there are any except for a few very similar lights coming on the market (Emilion's? Dae's?); and the performance of their switches remains TBD.
Mechanical clickies are a primary source of failure in LED lights as the rest usually has few/no moving parts. Over time, I've had problems with Kel-lite switches (broke), Mag-lite switches (broke), mini-mag switches (broke) , Arc LS clickie switchies (broke x 2), X1 switches (required cleaning), CMG/Gerber Infinity switches (shortened battery a little - needed a foil pad), and others I forget. It just happens.
My Fenix switch retaining ring once unscrewed itself a little with repeated removal ot the tailcap - fixed by screwing it back in tighter. Not perfect - but still pretty good. Could put a drop of loc-tite on it to really prevent recurrence if I wanted, but doesn't seem worth it right now.
Switch designs that have been real reliable for me (YMMV) include EL XM-3, Costco 1W 2AA luxeon, Lightwave Infiniton (true solid state switching) and new reverse battery Xnova 8's since the battery spring is in the head and the tail just has a fixed metal contact plate. But none of them can do what the Fenix does.