Getting that snare crack is a tricky one. You need an EQ to bring out the desired frequencies, a compressor that can really smash this shit out of a sound (PSP MixPressor is a good one to try), then combine that with a good gate to control the result. If you really want a super tight, consistant sound then samples will come into play at some point. Nobody says you need to 100% replace though. I often dial in a 50% mix to give a little extra snap. In a pop-punk mix I finished this weekend the snare was already sounding pretty punchy with loads of snap, but I mixed in a lower tuned sample to give it some more weight. Worked a treat.