Take a look through the background for the race you're interested in, maybe play a trial game in a Games Workshop store, and, if you find the Orks fun to play as and find their fluff interesting, then by all means, go for it!
Personally, I'd say no, but that's because I much prefer the Fantasy Orcs, and don't really see Orks as gun-toting warriors in the future, so I chose to avoid them because I don't really like the background. Having said that, gun-toting menaces that just love to go crazy and live for the fight may be just what you want.
If I was going to recommend an army, I'd say either Imperial Guard, Chaos or Space Marines, mostly because those are the armies I enjoy playing as, so I'm bound to recommend them.
Still, like I said: if you enjoy playing as the Orks - and I'd definitely recommend asking about a trial game - then, by all means, collect the Orks. If you like their background, seriously consider it. Also, the Orks have some awesome miniatures available, so if you like the look of the models, then go for it as well - I may not play Orks, but I pick up some of the models whenever I have some spare cash because they're wonderful to convert and look amazing.