LibreOffice. It's old-school local app though, not cloud.
There are several other Free Software tools that will provide spreadsheet compatibility, Gnumeric being among my favorite. Also the KDE office suite, KOffice.
I'll admit I pretty much only use it when I must for comparability. Otherwise my preference is plain text (vim) over word processors, awk for Excel, with lighter utilities (abiword, numeric, koffice) or specialized tool (lyx) standing in for more specific tasks.
To be honest, I too used the same toolset as you for a long time, but since Office 2007, it's just not been worth it for me. I have to share a lot of documents and information with people who don't understand the UNIX tools so it's not practical.
There are several other Free Software tools that will provide spreadsheet compatibility, Gnumeric being among my favorite. Also the KDE office suite, KOffice.