I just submitted to The Masters Review Flash Fiction contest last month—first place gets $3,000, which is solid for under 1,000 words. The caveat is their editorial taste leans toward crisp, literary prose with a twist; my more genre-bending piece got a polite pass last year. Another reliable one is the 'Saturday Evening Post' Great American Fiction Contest. It pays $500 for the winner and publication in a magazine my grandparents actually recognize, which is a weird flex but kind of charming. Not the hugest purse, but the prestige opens doors.
For pure cash, the BBC National Short Story Award is massive (like £15,000), but it's ultra-competitive and has specific eligibility around UK connection. I treat those as my annual 'reach' submissions. Honestly, don't sleep on genre-specific contests either—'Asimov's Readers' Award' or the Alfred Hitchcock's Mystery Magazine contest often have lower entry numbers and decent payouts if your story fits the mold. My strategy is mixing one 'dream' contest with a couple of mid-tier ones per season to balance hope and realism.