well i bought my first pda (HTC Universal) in 2006... and i was searching for software... the sites that i found most helpful were buzzdev, xda-developers and ppcwarez.
i really liked ppcwarez right away because i didn't have to register to view the forum, unlike most of the forums out there!
in my opinion ppcwarez is the best because it's really well organized and categorized. it is very easy to find whatever software , game or movie you're looking for. the search function is the best...
there are a lot of sites that are selling apps and are really a mess... i can't get the right info i want, no reports from other users if it's any good or not... and on ppcw i have everything, i get the full version, info, screenshot... basicly everything i need.
well that's why i donated , i wanted to support the site that supported me when i was a broke college student
p.s. also i need to say that i don't want to buy an app that i use once a week or once a month... however i think if you have the money and use certain software on a daily basis you should buy it. i use resco explorer every day and i did buy it, i'm still on the fence concerning spb mobile shell 3.0