Unfortunately I find myself doing film processing more and more infrequently (other things taking up time), and I fear that the Xtol I've been using may not hold up very well sitting unused for too long (I keep the working solution in an accordion bottle), when I did my last roll the developer was slightly yellow-ish and the negs came out a bit on the thin side, which I fear may be due to the developers age (I mixed it sometime in November). I've enjoyed the results I got with Xtol, but I fear that I may need something that will keep longer. I've heard that liquid concentrate developers generally last longer, as you can mix smaller batches of working solution at a time, the most oft-cited example being Rodinal, but I fear that Rodinal may result in a bit too much grain for me. I tend to shoot a variety of subjects (landscapes, portraits, 'street' etc.), and I oftentimes do push-processing and I use both traditional and modern 't-grain' films.
I've searched the internet and found people recommending Ilford DD-X (as it supposedly is somewhat similar to Xtol), which unfortunately is difficult to find around these parts, but I've also read about 'Studional' or 'R09 Spezial' which supposedly is like Rodinal, but with finer grain (and it is more readily available here), but I am unsure about the other qualities of it (tonality, speed etc). There seems to be a lot of other alternatives as well but I'm not quite about their various characteristics.