I think it is justified to say that almost all GNU tools are better replacements for venerable Unix commands, because they are more up to date (e.g. like the mentioned handling of large files), and offer many many more features through a bewildering array of additional options.
The guy who started issueing these tools and who founded the FSF (i.e. Richard Stallman) was obsessed by the idea that usable and useful software should be available free of charge, and free for anyone to extend these to their own needs by disclosing their source code.
Apart from those GNU tools already mentioned there are a few I wouldn't want to miss.
One that way outperforms the standard pager more is less.
It has far better parsing capabilities.
A real goodie is its 'F' command which switches an inspected file into follow mode (like what "tail -f" does).
Another great feature about less is that you can define a so called LESSPIPE.
Thus you can do a less on e.g. an HP-UX depot file (provided you have configured the lesspipe to pipe into swlist commands) to show its contents on the fly.
The same works of courese for tarballs, gzipped, b2zipped, compressed or whatever kind of archives.
So instead of always having to type
gzip -dc my_tarball.tar.gz | tar tvf - | more
you simply say
less my_tarball.tar.gz
Read the manpage of less to find out about how to configure a lesspipe.
If you can shell script a little its easy.
Then you should also get GNU's version of tar, which can do many more things than standard tar.
This is almost true for every GNU command.
Of course not to mention the great Bash, another GNU offspring.
But there is a slight drawback that when you got used to it you will automatically expect it on other Unices.
And since you got spoiled by the comfort (like all Linux users whose OS ships with GNU commands) it may ruin your day when you are confronted with a misdemeaning more pager on e.g. Solaris (which really is a pain)
Madness, thy name is system administration
