If you just want to kick back and let the good times roll, and aren't necessarily bothered about too much authenticity, there are plenty of fun restaurants in Cairo.
With ample supplies of beer and wings, a Hard Rock Cafe is going to be a fun restaurant no matter where it is in the world - and in Cairo, you have a Nile side view to complement your celebration. Farahat is a fun restaurant for a different reason: they serve arguably the best pigeon in Cairo, which is a great experience to eat since you pretty much have to tear it apart with your hands and suck the flesh off the bones!
Scarabee is a Nile dinner cruise which includes buffet and bar, as well as belly dancing and sufi dancing. Little Swiss is more gourmet style fun, with cheese and chocolate fondues, raclette, and traditional table grills.
The Cairo Jazz Club and the Buddha Bar are fun restaurants for those who want to party after eating, and L'Aubergine also gets really lively although it's more of a young crowd. The Greek Club can also get pretty raucous, and is blessed with cheap food and even cheaper drinks.
Eros doesn't serve alcohol, but has decent Oriental food and a comprehensive range of shisha flavours. The atmosphere is usually good in the evenings, and there's a DJ playing Arabic pop (though dancing is rare). The Grand Cafe is a fun restaurant chain across Cairo that is good for watching the football whilst supping a beer and a shisha in the open air, and has passable food to boot. Service isn't always the best, though that is arguably part of the charm.
Grand Hyatt Hotel, Corniche El Nile
Grand Hyatt Cairo
Rock out next to the Nile...
Corniche el-Nil Street
Dine While Cruising the Nile...
126 Al-Azhar Street
Traditional pigeon to coo over...
21 Mahmoud Bassyouni Street
Midan Talat Harb
Cheap food and drink in classy surrounds...
21, Road 254
Traditional Swiss Fondue and table grills...
197, 26th July Street
Ultra Cool, Jazz Venue...
1, 26th July Street
Good shisha and mocktails in nice setting...
3 El Thawra Council Street, Sofitel El Gezirah
Sofitel El Gezirah
Buddha Bar and Asian food...
5a Sayed El Bakry Street
Large selection of veggie food, plus a lively bar...
Merryland Gardens
near TGI Friday
Open-air oriental café serving shisha, beer and food...