The best replacement for gzipstream is deflatestream.

The best alternatives to gzipstream are rated as following:
★★★★★  deflatestream
★★★  sharpziplib
★★  dotnetzip

Your alternative for gzipstream is not listed? Suggest!
Speaking about gzipstream, one probably shouldn't forget about memorystream.

Other search terms related to gzipstream and their ratings are:
★★★★★ memorystream
You have in mind a companion for gzipstream and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of gzipstream in all years. Click on graph for more.
gzipstream
deflatestream
sharpziplib