I am facing similar decisions with regard to continuation of my training. I am recently OW certified, and have done a couple of tag-along dives with the LDS guys in different environments (colder water, rivers with current, etc) to improve my bouyancy and weighting efficiency. I also have already invested in a dive computer so I can correctly guage where I am falling short of my dive expectations (too many "rapid" ascents in shallow water, etc.). My problem is I go into the water with an intent to multi-task, as I am avid photographer and plan to capture lasting underwater memories, as well as work on my dive skills.
My goal is to maintain recreational diving as a passion, so I believe the next steps for me will be Nitrox, AOW and Wreck diving. The LDS is having a trip in May to Panama City, where I plan to complete all of that training, but in the interim, I am going to keep diving local rivers, lakes and springs to further hone my skills and to obtain that "perfect dive profile."
That's the goal, anyway!
I want to continue to improve with time, and am planning a birthday excursion to Bonaire, again with the LDS, for a week. This is the main reason I want to ensure I am Nitrox certified and am better familiarized with multi-tasking whilst diving. I've heard nothing but incredible things about the reef systems down there, since they are so protected.
I think Rescue is another good idea, but will probably seek that out in about a year's time, once I have a good familiarization with recreational diving, and have the experiences to draw on for "what-if" scenarios. Incidentally, in our NAUI OW class, we ran through a few "rescue" activities, that one of the PADI class attendees didn't have to complete. That is a curious thing to me, as I would think the training should be standardized to ensure rescue ascents with oral BC inflation and surface tows were requisite for all divers.