Can anyone recommend a romantic hotel in Las Vegas? We would like to be right on the strip, as we won't have a car. Thanks.

Bellagio.

Bellagio, or Venetian.

Those suites at the Venetian (especially try the brand new Venezia suites) are tres romantique! (Is that French or did I just make that up?) Whatever, you can't beat those rooms!!!

Venetian. Way less expensive than Bellagio.
And romantic, the rooms are very large with a bathroom to die for.
You might even like the canals.

The Bellagio! The suites are to die for.

Definitely the Bellagio. We went there for our anniversary. Be sure and get a room facing the fountains. The windows are picture windows that take up almost the whole wall. At night put on the comfortable robes supplied, pull the two chairs up to the window, turn the stereo to the fountains music channel, and watch the fountains display right in front of you to music. Also Paris is across the street so at night you have the Eiffel Tower all lite up behind the fountains. It is just gorgeous and very romantic. We had room service deliver us a late supper and it was very nice.

bellagio facing the fountains

Venetian--standard rooms are huge, like mini-suites, and have huge beautiful bathrooms.

Are the Venezia Suites at the Venetian in the new building? Are they more expensive? Are they a further from the casino?

Venezia rooms are in the 'new building' and are farther from the casino.

Bellagio's suites are the best under $500 rooms on the strip IMO (the Bellagio Suites in particular, as opposed to the Salone Suites. Penthouse Suites are better still, but can run more than $500 depending on dates).

LynnB -- I will push the Venetian for this one. Even the most standard suite offers luxury and you can ease your budget by bidding $100-120/night on Priceline (I think it's the only 5* strip hotel Priceline works with). We did this and had a 750sq room with a separate living room, large screen tv's in both the bedroom and living room (not that we used them), 3 telephones (one in the bathroom!), great bathroom with separate toilet area/shower/bathtub. Also, a great location.

Four Seasons....

I love Venetian, but Four Seasons would be my choice for the OPs purposes.