Well if you want higher quality and you are US based, Tennis TV is a great option because they pretty much have everything outside of the Majors and first class replays for one week, and a fine value for $129 per year. In the US some of their coverage gets blocked. Fecaleagle recommends Private Internet Access VPN which for a year is $48; this will get you by region block for some of the minor US based events that Tennis channel or ESPN have the rights too. VPN services temporarily give you an IP address from the country you select (they have servers in each country.) VPN is a minor thing as we are talking Houston, Newport, Citi Open, and Atlanta. (Tennis TV has a lot of WTA and the VPN service may or may not be helpful either.)
Sling TV comes into play for the majors. If you don't have cable with ESPN, then Sling gets you ESPN and ESPN2 proper and all their commentary, plus its gets you the login for Watchespn so you can use ESPN3. Now if you have ESPN, then you need to get your email/password for that account and just use that for ESPN3. Tennis TV has superior replay to ESPN, but they don't have it on Android and IOS which is all phones and tablets. ESPN has replay on those devices. However, Tennis TV has 10 second forward and 10 second rewind on live matches while ESPN does not have any DVR functionality on live matches. This is a huge thing as you can pause and jump through (click three 10 second advances between points to catch up in a Nadal match.

) Some internet providers do give you ESPN3 access; I just got rid of AT&T who does that. This may work well, but you don't get the ESPN and ESPN2 guys commentary and strictly get the same commentators that you'll hear with Tennis TV.
For US Open I do Sling. I just subscribed again and got my third 7 day trial and then I'll let that renew for $20 for the US Open (you can cancel online weeks before your next due date or call them.) Winston-Salem Open is not on Tennis TV, so ESPN is a great for it. I tried for Australia to get by with 7 days for the last week and batman for the first week, but ended up forgetting to cancel and getting a full month of Sling (which gets you about 25 of the most popular cable channels.) This will also work for Wimbledon, but not the French Open which ESPN doesn't broadcast anymore.
I used an VPN service like Private Internet Access VPN for the French Open and Wimbledon and had reasonable replays and the UK based commentary was nice for Wimbledon with lots of extra shows available on the BBC website (I did How to Watch French Open and Wimbledon threads with more details on the international sites.) Most VPN services can be done month to month for $6 per month and Easy Hide IP has a free three day trial which is a great way to start with your first VPN experience. I hope to watch Australia this way. If you don't want to mess with VPN or understanding these sites, then just cough up $20 for Sling at Auz and Wimby. At the French a VPN service is a must. All of the international sites have very high quality video that looks like full 1080p (1080 x 1920, but is usually 540 x 960 which still is near high def.; 720p is 720 x 1280 pixels.)
VPN service can get you an upgrade from Batman that isn't really high def, but is way better than Batman streams. I used a Canadian IP address and From Hot --
http://www.sportcategory.com/c-4.html has been a high quality alternative to batman stream. You don't need to worry about ad block so much with From Hot.
The prices:
1. $48 per year for Private Internet Access VPN and just use From Hot -- probably a great choice for tablets and ipads on the go where resolution takes data and is not as critical on a small screen. You can try to economize and sign up for month of VPN service when needed at $6 per month and do one of the more expensive options that follow.
2. Add Tennis TV for $129 per year. If you really want to be cautious you can do the first month for $20, but better to go annual on this one. Tennis TV in review gets you crazy good DVR and basically everything, but the slams.
3. Sling TV at $20 for US Open and Winston-Salem Open (they allow multiple 7 day trials, so you can be a complete cheapskate and probably get a free 7 day window at US Open, French Open, and Wimbledon for the last week and From Hot it the rest of the time.)
4. French Open is definite VPN service. Tennis Channel has the US rights and they might get their act together. In 2015 they allowed you to get their watchespn equivalent for $13 for one month, but important matches like the Friday morning SF were not available unless you were a Tennis Channel subscriber (which is a huge annual expense with full cable contract and often a sports package.) 2016 was worse as to get the French Open you would have to sign up for entire year for $80 just for the limited watchespn equivalent and they probably blocked a bunch of stuff again. NBC broadcast stuff is a train wreck too as they require you have some type of cable to get access to their NBC sports app. Hoping in 2017 Tennis Channel does better and the new ownership is leveraging themselves into more standard cable packages (like the Golf channel). Hopefully they reintroduce monthly pricing for a much more completive watchespn equivalent. At this point the service is just a thorn in the side of Tennis TV. The thorn's poison can be overcome with VPN service except for the French Open. I'd love to pay Tennis Channel and support them, but this is like $1000 on an annual basis, and I don't watch TV per se and hardly touched Sling TV after the Australian Open for the last month I had it.
Recommendations:
1. Deluxe (what I am doing and any serious tennis fan deserves; just economize on your internet, TV and phone like Meles

who pays about $43 per month for nice internet service and cell phone service). Deluxe is VPN service $48 per year. Tennis TV $129 per year. Sling TV for $20 for US Open period. (Brad Gilbert and Co. addicts add another $40 per year for Auz and Wimby) That's $197 per year for the Meles Deluxe high def DVR top of the line viewing experience ($237 for Brad Gilbert addicts).
2. Deluxe tight wad. Tennis TV $129 per year. Sling 7 day trials for Auz, Wimby, and US Open last weeks (free

). VPN service month by month, but includes 5 months starting around French Open and possibly another month for Houston. $30-$36 which gets you by the region blocks on US events and gets you HD at majors when you don't have your Sling trial. $159 per year total. (Save $38 over option 1, but it’s almost like stealing from Sling.)
3. Batman stream on steroids From Hot option. $48 per year for VPN service and use From Hot for everything. No replays, but higher quality. For the majors you should be able to get very high def feeds and the supplement with the Sling 7 day trial as in Deluxe tight wad. $48 per year and you'd have just as good quality on majors as Deluxe tight wad.
4. Lawful Good option - do the Brad Gilbert deluxe option above, drop the VPN service, and don't watch much of the French Open. $189 per year and you feel completely clean and ethical in all ways, but it’s hard to be good when Tennis Channel has rendered the French Open almost unwatchable at a reasonable price. If you lawful gooders want the French Open, then sign up for full cable and necessary options and maybe your only out $750 plus the $189 above.
I'm never writing this again and have made a copy of it. Enjoy cutting the cord and having a stronger tennis experience!
Oh yes, and Sling TV is the bomb. Gets you cable tv on all your mobile devices and unique features like Monday Night football which Watchespn does not even do for their mobile junkies.