Is there a prize for the 100th person to ask generically for South Beach recommendations without reviewing the board first? Here's the last one, which I think was number 542, and is only 13 posts down and still on the front page of the board ->
Here's another recent one about 25 posts down ->
OK, with the snark out of the way, let's get down to business, focusing on "highly seasoned food" as a cue.
For me, I think the best food on South Beach, hands down, is at Talula. Also fits your bill for highly seasoned (though not necessarily spicy - just great, bold flavors). The tripe cassoulet I just had there this weekend was outstanding (Miami, like your native New Orleans, has been undergoing a real cold snap and it's a great opportunity for hearty fare like this).
I like the Italian food at Sardinia which has a strong regional focus (i.e. the name) which provides some dishes that are different from your run of the mill Italian - spaghetti with bottarga, clams with fregola, roasted suckling pig.
Indomania is a neat little place with Dutch-Indonesian food, the rijstafels, with about a dozen or more dishes, are a lot of fun.
Meat Market on Lincoln Road has been getting a lot of love lately; one of a multitude of steakhouses that have opened up the past couple years, but this one has a little more flair to it. I've only been once shortly after it opened, other more recent experiences were more consistently good than mine.
But c'mon, do a little reading!
Note that Douglas Rodriguez also has a brand new restaurant in South Beach, De Rodriguez in the Astor Hotel, which has more of an exclusively Cuban (contemporary) focus, whereas Ola is more "pan-Latin."
Note also that these responses focus exclusively on South Beach. For some of the best food in Miami you need to get off the beach.