We are in our 20's and from NYC. Looking for upscale and fun dining and bar options.

Between A1A and the next street inland in South Beach, you can walk from one fun place to the next.
There are so many. Get yourself a Zagats of South Fla. and go by what they say. They're pretty accurate. You may only not find the brand new places in there.
I remember China Grill (I think that's the name) that is definitely a happening at least for the 30-50 group, but a bit upper end. Fun and unique dining. You must call ahead for reservations esp. for weekend. Can't tell ya the names of the bars that they Latin dance on the counters, but keep inquiring cause they say they're worth it. Good Luck

Go to Tantra, lots of beautiful people, very hip, but be warned, take lots of $$$$$!

A great dance spot is Crobar. Reminiscent of the old NY clubs like Limelight, Studio54 and Xenon but with new music. If you like to dance or just watch people dance, it's a lot of fun. If you ask at your hotel they will probably give you a coupon for free admission (normally $20).

Lots of dining on Lincoln Road (though can be touristy). You can check out the South Bch twin of NYC's Sushi Samba. Touch has eclectic food and nightclub feel. Trip to South Bch is not without a drink(s) at Schrager's Delano Hotel. They also serve food off the lobby. Sleek pool and cabanas in the back are great. Has similar Hudson / Royalton feel.

Like the others have said, there are a lot of choices in the South Beach area (Lincoln Road, up and down Washington, Ocean and Collins), and the prices will be comparable to NYC (that is, high). Tantra and B.E.D. were the restos-of-the-minute for a few minutes in the last two years, but the darling of the critics is Wish, in The Hotel. Touch, on Lincoln Road Mall, is also well-regarded. I've heard mixed things about the Blue Door at the Delano, but....

Nightclubs? The scene is still hopping, although there's less Eurotrash and more New Jersey tourists in the clubs. Level is always a trip, probably worth a visit. Nikki's Beach Club (if it's still open-- who knows any more?!) is fun too. Check with the concierge at your hotel. Note that the scene is very gay- and lesbian-friendly, so if you're uncomfortable with guys and girls dancing together, you may want to party down in Branson MO (just kidding!--)....

Delanos is a very cool bar - but service?? No drinks list is produced instead we get a response from the moron waitress "we have everything". Ask for a Tia Maria "whats that -a cordial?, no we do not have it" - yes they did.

Have drinks at the Delano but skip the Blue Door for dinner. It's mediocre. I had a great brunch at the Tides. I'd like to try dinner and drinks there next time. Nikkis was recommended for Sunday afternoons but I didn't get to it. Try Opium for dancing if it's still there. (I haven't been to SOBE since Nov 2001.) I had a blast!