I recently returned from Dominican Republic and this is my experience and/or research:
Hilton La Romana - been here twice, hotel is very nice and food is generally good, but on most recent visit the restaurant menus have been cut in half (in the sense that there are about half as many options available). I feel the food was better the first time around, but overall still 'pretty good'. Service was great and many of the staff remembered us from our last visit and knew right off the bat the drinks we liked and how to make them. As the name implies this is in La Romana, which is far from Punta Cana (60-75 minutes / $100 taxi), so a very different atmosphere than what I picture the 'party' atmosphere of Punta Cana to be like (i have not yet been to Punta Cana 'proper').
Ziva Cap Cana - supposedly one of the premier all-inclusives in DR. Unfortunately we never got to go as the hotel closed after hurricane Fiona(??) came thru; hoping to visit at some time in the future. The hotel is once again open and (as far as i know) fully functional.
Dreams Macao - we chose this resort to 'replace' our Ziva stay above. Overall the hotel was equivalent in terms of quality to Hilton La Romana, with some aspects being better and others being worse. Dreams has the edge on layout and the number of restaurants (especially if traveling with children since Hilton has an adult side and a family side, with the adults being able to crossover to use the extra 3 restaurants on the family side, but not vice-versa). Service at the Hilton was a bit more polished (although at both locations the staff seem eager to please) and the drinks were much better. One thing about Dreams that turned us off was that there were flies almost everywhere, and i'm not talking about 'some flies', i would say easily 30-40 flies would land on a plate as soon as a table was vacated. I don't think there is too much the hotel can do about it, and apparently it's not usually an issue but we happened to be there when there were storms offshore which apparently caused an influx of flies to come ashore, but it prompted us to eat indoors for the remainder of our trip as it was just not appetizing to see (nor to swat at flies while we were eating). If i recall correctly we paid about $250/nite per room (which was quite a bit less than most sites were offering it at the time) which was a very good deal and felt it was an excellent value for the price paid (may have been disappointed if had paid 2x as much).
Finest - i don't know as much about this one but this was the other option many people booked when Ziva had ceased operations in order to perform hurricane repairs (these have since been completed, afaik). Supposedly it's on par with Dreams Macao.
I'll add to the above that we travel as a family (two teenage daughters) and for all-inclusive vacations we mostly like to sit around the pool and relax; not interested in loud music, the organized nightly entertainment, etc. We spend some time at the beach but it's not the main focus of our vacation. If you're looking for music all day Dreams (at the main pool) is probably better than Hilton, although i would not consider either to be 'party' resorts so if that is what you're seeking there are probably better options out there.
One more thing which you probably know but i'll add for anyone else that read this, is that many of the all-inclusive properties have 'preferred areas' that cost a little more which give you access to additional amenities (each hotel's offerings are a little different) but typically include: a private pool area, upgraded liquor, extra restaurant options, a lounge area with snacks throughout the day, private check-in/out, occasionally a butler, etc, etc. We had 'preferred' at both Hilton and Dreams, mostly for the private pools (since we like quiet and also don't like to get up at the crack of dawn to reserve a lounge chair in the shade) and the premium liquor.
Lastly, I recommend DAT (dominicanairporttransfers) to get around the island. We used them on our last trip as well as this recent one and they have always been at the airport waiting for us upon arrival, as well as ontime for our departure, and their prices are competitive. For this last trip i did try a different company (which shall remain nameless) for our hotel-to-hotel transfer as it was a bit cheaper, but given the driver showed up 20 minutes late (and never called until he was 15 minute late), thought we were going to the airport when our reservation indicated we were going to another hotel (which he acted as if it was my fault and was upset with me for it), and talked on his phone for most of the 90 minute ride will have us sticking with DAT in the future (or at last one of the other major companies).
