My MiKTeX installation is under 1 GB (MiKTeX pulls packages on-demand, so there aren't gigabytes of unused packages on your disk) and the excellent TeXstudio ed

My MiKTeX installation is under 1 GB (MiKTeX pulls packages on-demand, so there aren't gigabytes of unused packages on your disk) and the excellent TeXstudio editor has a spell-checker enabled by default. ShareLaTeX is excellent for collaboration, but I much prefer a local setup when that's unnecessary.