Thank you everyone! Coda alla vaccinara sounds really good, because especially I am crazy about oxtails. I must try Cookbookchick's greek stew too. Well, all the ideas are really helpful. Thank you again.

Braised celery is one of my favorites. Here's a link to a great one on 101 Cookbooks blog: http://www.101cookbooks.com/archives/000946.html

One of my favorite celery recipes is Lidia Bastianich's celery chutney http://www.grandparents.com/gp/content/food/recipes/article/celery-chutney.html

I love all of these recipe ideas. If you have leftovers, you can also chop, blanch, and then freeze the celery in recipe-sized portions for later use in soups. I have found very little reduction in flavor quality. http://realworldfoodie.blogspot.com/2010/02/quick-tip-celery.html

I will ditto Amanda on coda alla vaccinara. Celery is very popular in Roman cooking. When you purchase it go after bunches that still have the leafy tops. I hate it when markets trim them off because they have so much flavor. My own recipe is http://www.food52.com/recipes/2741_and_now_our_tail_comes_to_an_end_coda_alla_vaccinara

Here are some interesting celery recipes:
http://www.epicurious.com/recipes/food/views/Apple-Celery-Granita-238975
http://www.epicurious.com/recipes/food/views/Sweet-and-Sour-Celery-352284
I'd also consider pickling some!

Creamed celery. Gently boil sliced celery (about 1/4-1/2 inch thick slices) in slightly salted water until they're al dente. Save the celery stock, and make a cream sauce, using 2T butter, 2T flour, 3/4C full fat milk (or cream if you're feeling decadent) and 1/4C of the celery stock. Bring to a boil, reduce heat and simmer until the sauce is nice and thick. Plop in the cooked celery, and season to taste.

Don't toss the leaves from the bunch/head of celery either. They're fabulous mixed into a tuna/potato/ham/pasta salad, or into a soup. There's tons, TONS of flavor in celery leaves.

The most recent issue of Fine Cooking had a bunch of recipes for celery, both raw and cooked. There were a couple of salads that sounded really interesting, I clipped the recipes, but haven't tried them. Here's the link to the Fine Cooking site with a bunch of other celery recipes....http://www.finecooking.com/item/5154/celery

IMO, celery is a vastly under-rated vegetable.

Can you explain more? Why cook it? While I agree celery is great cooked in soups..or even with just butter and simmered a bit..and flavoring for stocks.

I think it's major shining star is the crunch and fiber while it's raw. In egg salad, stir fries, salads, or even in a Tabbouleh..with quinuoa, parsley, cumin, lemon juice, olive oil, and feta cheese. (add a chopped chicken breast or tuna on top for a full protein meal).

Although..one recipe..is using celery seeds, and celery. Boiled down with simple sugar.
Use that to mix with soda water for drink to serve with corn beef on rye and sauerkraut.

A Greek pork stew with celery is also very good, especially finished off with an avgolemono (egg-lemon) sauce such as you find in Greek chicken soup. The lemony flavor plays off nicely against the celery and the richness of the pork.

Coda alla vacchinara (braised oxtails with celery) is a great dish, often found in Rome. Here's a recipe for it -- and if you don't like oxtail, just substitute shortribs -- http://tmagazine.blogs.nytimes.com/2009/11/19/now-serving-when-in-maialino-recipe-included/