We always stop in Puerto Rico in october ,as the bars and restaurants in PR are in 2 large shopping centres (Puerto rico shopping centre ,at the bottom of the hill & the Europa centre ,at the top),
PDI is 5 smaller centres dotted round and about PDI ,I stopped in PDI in july 03,but prefer PR by miles ,I think PR is based more around British tourism than PDI.
If you do choose PDI ,you've got to go to the Yumbo centre and see the drag shows.

We 've paid £238each s/c in Puerto Rico for 7 nights.

Sorry but i can't comment on Playa del las Americas never been!

Anyway have a great 21st wherever you choose to go
Vicky

Nightlife is generally good in October. There is really not so much difference between Playa del Ingles, Puerto Rico or Las Americas regarding nightlife. It's more a matter of personal taste. Of these three I prefer Playa del Ingles, but I also like the two other places. I guess if I were you I would just settle for the cheapest option of any of these three...

Puerto Rico has decent nightlife. Last time I went to Las Americas it was dirty with rats running around.

i have been to all 3 and i would rate puerto rico as a lame 3rd for night life. just wasnt that great. playa des ingles was good. irish quarter and and the kasbah are good fun. but best place has to be playa de las americas. its not run down and i saw no rats. veronicas is fun but i prefer starcos and the patch. there are so many places to go and the night life is just fantastic. if you want to be boozing until early hours i would choose las americas. i think the other two resorts are ok but nothing special night life wise. i was in las americas is july and i was very sad to come home