I'm currently really into the idea of having our invitations and/ or envelopes be a bright color - cobalt blue, red, pink, orange, or turquoise - with white writing, similar to this logo for the blog of West Egg Design's Amy Wiltbank. Great font too!
I'm loving fonts that look somewhat handwritten like this invitation below:
Some samples from a calligrapher that I like Pen & Ink Calligraphy, although I don't think calligraphy is in the budget!
I've blogged about this "font" before that was used on an invitation by Linda & Harriett but a graphic designer friend recently pointed out that it's not a font at all, it's custom (you can tell because no two letters are the same) - shame!
I'd been starting to seriously lean towards nothing decorative on the invitations, text only, until I saw this honeysuckle print on this Little Tree Press invitation - adorable!