I'm a little late to the game here, and I don't know how big of a company we're discussing, but a few things I saw in the thread:
You need something universal. What does everyone need or will appreciate? These are my OPINIONS, so take them as that.
Food is great. Food at work is better. If you try to reward me with a dinner out with the whole office, I'll find something else to do. I just spent 40 hours a week with these knob-heads, I don't want to feel forced to socialize with them after hours. It's also a little hollow IMO. It's a money dump. Here's food, I'll pay, now be happy. You'll have some who say they would rather have a cash bonus, others will grumble that they don't see their family enough anyway, and that one guy from accounting who says "I've asked for a hole-punch for three months and was told we couldn't afford it, but we can have steak for 15?" Food at work allows people to make their own mix of social and work time. Jerry really needs to finish his spreadsheet before the 2pm meeting, so he might grab a sandwich and go back to his desk. Bill has been working his tail off with the new account and has a moment to breathe, so he hangs out at the dessert table talking with Heather and discovers they both like kayaking. That's team building.
Cash is nice. I, personally, am not money-driven. It takes a lot of money to perk me up, so some won't appreciate the cash necessarily. Hard to believe, but if I work my butt off for $50k/year, a $1000 bonus is not only a little "really, that's it?" but it also has no heart. I feel purchased. Like getting a gift card... which some people like.
Activities are sometimes fun... if you're an extrovert and if you like the activity. It also (like dinner out) may have an "overtime" feeling to some. Rest assured, it will be received differently by different people. If you, as my boss, hosted a laser tag event, I would gladly sit in the snack bar and wait for you all to be done. Others would LOVE it. I think you would also need to choose events that are sustainable. By that, I mean choose events that people can look forward to without having to take it away later. Imagine having a yearly potato sack race and then two years from now you hire a paraplegic, or an overweight person who feels singled out. It would suck to have a quarterly axe-throwing night and then hire a person with Cerebral Palsy.
My first choice would be food at work. Then it's like a free break. The social people can take the hour and chill by the buffet, the introverts can appreciate the food at their cubicle and watch facebook reels. My last boss had what he called mandatory staff meetings every Friday at 2pm. He would have something inexpensive every week; mimosas and a cheese plate, champagne and a veggie tray, root beer floats and cookies. We just had a drink and chilled out as we felt moved to. Lots of laughs and bonding.
Second choice would be money and/or PTO. I can extrapolate that money (while lacking heart) is something that 95% of the world would appreciate and I would like buying car parts with it.
Just my thoughts, but I realize I'm not normal in many ways.