Need opinions and recommendations...

How about a beagle/lab mix?? In the midwest they are quite common and are often the best of both breeds. Checking into breed rescue for any of those breeds would be a good idea as well since they tend to know more about an individual dog's personality.

If you want a great guy's dog, how about a boxer? They are a GREAT size and great buddies for a ton of different activities. My fiance has one and loves her - she's got a good balance of energy when you want it and can sack out nicely if she's been exercised. She's a sweet dog, and definitely has a very happy-go-lucky personality, but isn't close to my BC in energy level/endurance.

I had a boxer and she was by far the best dog ever...and Im not saying that because she was my dog...but every boxer i have met has had a lot of health problems.  When we put her down she had cancer, ulcers, and heart problems.  It was hard with her having those problems.  And they have lots of energy...  I would have already gotten a boxer if it wasn't for those reasons.

I'll attack this from a different angle.  I wouldn't say the breed matters nearly as much as the AGE of the dog.  I'd tell you to get a dog that is 2-3 years old -- old enough to be active when you want to be, but old enough to be housetrained and settled.  Even a 4-6 year old dog wouldn't scare me in the slightest. 
 
Maybe you're brave enough to try Animal Control, but a dog that has gone thru a rescue group and has been fostered in a home -- you'll know more about that dog.  You'll know how vocal it is, and if it's used to a crate.  Often a dog that age is incredibly grateful for a good home -- they're ready for fun when you are, and yet they are also more than content to wait for you to get home from work and just relax at times. 

Beagle...
will depend on the dogs personality. As more and more people breed for "pet temperment" Beagles alot of the old "truths" about the Beagle are falling away. I have to Beagles in our rescue right now...one would do great in your situation ( was a pet)...the other would eat your house ( was a hunting dog).
Jack Russel...
I feel there has to be a good reason that even rescuers of russels call them "Jack Russell TERRORISTS" ...but that is about all I know other than I do not like them! LOL!
Lab...
personally...the health would worry me...and if you feel a Lab would be too big...well that kind of answers that...
BullDog...
do not underestimate a bulldogs energy level...but they are great dogs.
 

I am gonna throw out a small dog... dachshund.  I thought of this because you said you're a guy and single and you want a dog you can play with.  My bf was against me getting a small dog.  After getting to know her all of like a day, he fell in love.  He plays with her, chases her, naps with her, constantly comments how cute she is, walks her, etc.  Also, whenever we go out, people come up to us to see her.  We joke if we broke up, he'd just have to get a dachsie to get a gf because everyone thinks a guy with a small dog is cute.  I do know other men who have dachshunds also.  Keep in mind there are minis and standard (which can be up to 30 lb. if you want a big one).
 
 
Some hunt (and can be trained to... the people I tutor had a hunting dachshund).  They are playful.  They hike. Dachshunds LOVE to relax and cuddle so they are fine in appts.  Short haired and wire haired dachshund barely shed... I don't think long haired ones are bad either, but not sure.
 
My only issue would be leaving them long because of the small bladder but Zoe is often left 8 hours without a problem and can go overnight much longer than that.  She does occasionally pee in her crate but we have a reusable pee pad in there that absorbs fast so it is not a big deal.
 
There are many dachshund rescue groups that you can talk to to make sure you don't get one that would bark too much . Also, [linkhttp://www.hua.org]www.hua.org[/link] adopts all over the country and has a bunch of dachsies (and other breeds).  Let me know if you need more info on the breed or other rescue groups.

daschaunds are great dogs...they ALWAYS make me giggle!

If you like beagles but want something bigger and are interested in hunting, what about coonhounds?

They're in shelters and rescues all across the south and midwest, piles of them.

While beagles are happy and silly, coonhounds tend to be a bit more serious and wry about their wit. They share the downsides possible with beagles: vocal and may not appreciate being left alone. But I've yet to find a breed of dog who universally is fine being home alone and never makes a sound. It all depends on the individual and also how willing you are to work with the dog to find the situation in which the dog is happiest while alone. On the whole beagles tend to be more pack-oriented than coonhounds and may have a harder time being alone than their larger relatives.

I think a 3-4 year old coonhound who's been in foster care in a pet home (sometimes it takes some adjustment for a hound to go from being 100% working to being a pet who also sometimes works) would be great for you. The foster parents can tell you about their vocal level so you can be matched with a quieter individual. I thought I'd really done it when I adopted Marlowe, my black and tan coonhound (in my avatar) because he barked and howled LIKE WOAH at first when I brought him home and tried to crate-train him. But what it took was me working with him to find the right balance of safety (which is why I like crates) and his comfort (he didn't like the crate) and all of a sudden--silence. Except for the soft sound of "zzzzzzzzzzzz" emanating from the easy chair he spends his days napping in. It wasn't that he didn't like being alone, it was just that he wasn't comfortable.

Whee! I don't get to recommend coonhounds often!

you mentioned the reason you didnt want another boxer were the potential health issues. if i am not mistaken bulldogs are prone to many health issues.

just something to think about.

if you are mainly looking for a companion dog, there are many mixed breed dogs in rescues/shelters that would make wonderful pets.

BOSTON TERRIER! They're similar to Boxers, but smaller. Also similar to Bulldogs, but a little more energetic, smaller, leaner, less expensive and less health problems. Smooth haired, basically no grooming. Very smart dogs that love to please and learn tricks, great for apartments with moderate exercise. They seem like a great fit...

http://www.dogbreedinfo.com/bostonterrier.htm