Nowadays, personalized vows are probably heard more often than the old familiar "for richer or for poorer, for better or for worse" (which is actually the Episcopal vow, and not universal). As many couples, and not a few officiants, have noticed, it can be difficult to write from the heart when you don't have any basic format as a starting point.
Before we get down to specifics, let's look at the basic elements of a successful ceremony. There are five tasks that must get done somehow if both participants and guests are to understand and appreciate what's happening. And they must be done in the right order:
1. Get everyone focused on the event. This is usually done with a song or musical piece (here's where the wedding party enters!), a spoken greeting, and (in religious ceremonies) a short prayer.
2. Set the stage for the main ritual. There may be readings, songs, and/or a speech. If this material fills about 20 minutes, that gives the bride and groom time to relax and focus on what is to come.
3. Perform the main ritual. At a wedding, this usually includes vows and a ring exchange.
4. Re-integrate the major players into the community. After the vows, there is often a time for additional rituals that are traditional in the community, such as holy communion, lighting a unity candle, asking guests to say words of support, or something as simple as applause when the officiant announces the newly married couple. Some traditions do a lot here; some do almost nothing. If the bride and groom have no relevant tradition but want to do something here, it's an excellent spot for a blessing.
5. Create a sense of finality. We want to end with a bang, not wander off with a whimper. The traditional ending to a wedding ceremony is a procession, set to music, of the wedding party out of the wedding venue.
Within this framework, vows and ceremonies are strictly a matter of personal taste (assuming you don't have a religious tradition that sets the format of your vows). I've made a list of Web sites with wedding vows that strike me as particularly fun, thoughtful, or spiritual. It's unlikely that anyone reading this list will like all of the options!