I highly reccomend the Alesis CLX-440, which has 4 channels (2 dual stero linked channels))... Current price as of posting is $200.
If your on a modest budget, not only will you get more channels for the money than most other decent units out there (like the dBx)... but I suggest you make good use of the noise-gate/expander which may be just up your alley if you play with a rock band... The noise gate is IMMENSELY important on the drums, especially if your looking to do some more elaborate stuff in terms of recording, other than just "jamming" in your house.
The CLX-440 is not only a full featured compressor, but a full featured noise gate/ expander... so it's like getting 2 seperate pieces of equipment in one unit... Yeah!
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If $200 is too much, or if this unit is not for you, then my second suggestion is
SAMSON S-COM-PLUS compressor. Its currently retailing in stores for about $115.... and again, if you want the noise gate.. [which is important for drums], then Samson makes the S-gate-4 which is a 4 channel full-featured noise gate for about $120. The two Samsons together are $235 roughly; so why not go with the Alesis CLX-440 since its cheaper and has both units in one....