Still the best raster format and supported by nearly all GIS and GPS mapping programs. Sure the file sizes are larger (pretty much irrelevant with large gigabyte drives these days) but unlike JPG and PNG there is little loss of quality no matter how many times you import and export it. It's like the difference between "lossless" compression on a CD and the lossy compression of an MP3 or making a copy of a copy of a copy of a cassette tape. Plus a GeoTIFF and a JPG use about the same amount of memory since the JPG is uncompressed into memory and larger than the compressed file size. Once uncompressed it takes up about the same amount of memory as a TIFF anyway so there is no advantage