Bl Richard Mueller X L. purpurata
Bl. Sunset Glory has been the most successful starter orchid I have given away to beginners because it grows fast and blooms even before the new lead matures, any time of the year, both in water culture and S/H.
All hybrids of Bl. Richard Mueller I have tried also grew as easily for me but did not grow or rebloom so quickly. This plant also seem to grow aboundant roots early, and has shown more resistance to rot than any other cattleya type I have tried.
This my daughters first orchid. It rebloomed in a couple of months after I gave her a division in a 6 inch S/H pot. It is on an East facing window sill in a Chicago High-Rise. ( I would recommend supplemental light in the Winter in the North for most cattleya.)
Of course the Oncidium Sharry Baby growing in a vase, that she got a little later, also convinced her that some orchids thrive even on a windowsill. It now has a huge flower spike that scents the whole apartment.
This is a link to Onc. Sharry Baby growing in a vase.
Onc. Sharry Baby in water culture