On the appropriate occasion, nothing, absolutely nothing else will do.

The distinction between white and black tie has diminished a bit over the decades, but it still has a meaning, and being in the wrong tie is a minor faux pas.

And, don't forget....tuxes are black. Only black.
(White and ivory are for bandleaders)

There are times when a tuxedo is the only way to go. Done two of these myself (prom and wedding [not my own]) and I will say that the tux you pick for these makes all the difference. I go for the understated look myself. Not too fancy, just neat, clean lines, something where you are the finishing touch, and not the tuxedo. Same thing goes for a suit and tie for slightly less formal events (classical music concert, holiday or normal church wear, etc.): Keep It Simple Stupid. No sense getting so fancy that the suit overpowers your own personality. Again, I go for clean lines, simple subtle pinstripes (blue on blue or grey on grey are favorites), and a tie that complements the suit (e.g. not too loud). Also, having your suit or tuxedo properly tailored is important. It should complement your form, rather then show off the worst parts of it (I won't name mine). Then it's time to take a step down from there (normal church wear during summer, etc.) and either lose the tie, jacket, or both. Again simple is best. I don't see the need to go loud when I'm trying to go "formal." Give me a shirt with a subtle pattern and clean lines, either a complementary tie or a lightweight jacket that looks sharp (not both), and simple dress pants that don't clash, and I'm set.

I went to a formal affair on New Year's Eve. Very appropriate and very stylish. Such is always a special occasion!

To be worn after 7:00 p.m. and never on a Sunday according to Frank Sinatra. There is also apparently some rule about when you should have the silk stripe on the outseam, but I can't remember it. I know fashion is cyclical but I'm glad to see that formal dressing is coming back into vogue, and that the whole Casual Friday phenomenon has run its course. In my office people were starting to wear Friday attire all week long and the Friday ensemble had degenerated to things I would wear when I'm painting the rec room.

I dont own one but love the chance to sport one when the occasion rises. I will probably purchase one the next time it comes up. Rented tuxes only look so good because of the fit, but you can have them altered. Black only and not too "pimpish" please.

Its one thing to see a man in casual clothing because anybody can pull that look. But to actually see a man in a suit reveals a lot about him as a person, unlike casual wear that can just be thrown on the suit takes a bit more time to prepare and not all men look good in them. I think its a bonus if men can pull off both the casual and suit look.